2M Micro-Miniature Circular (Micro 38999)
Amphenol's micro-miniature circular connector family, built for the push to shrink military and aerospace equipment. As an Amphenol authorized distributor, ADMTEC supplies 2M connectors along with backshells and shrink boot accessories in Korea.
2M Series
What 2M is
2M is Amphenol's micro-miniature circular connector family. It came out of the growing demand on military and aerospace platforms for something smaller that still holds its performance, and the manufacturer presents this family as the industry's broadest collection of micro-miniature connectors.
The manufacturer calls one branch within it the 2M Micro 38999 product group. The name makes it easy to mistake these for MIL-DTL-38999 specification parts, which they are not. Please read the caution below first.
- Product families
- Amphenol 2M Micro-Miniature Circular
- Manufacturing division
- Amphenol Aerospace
- Coupling
- ACME thread (dual-start · tri-start) · bayonet · push-pull
- Contact sizes
- #12 · #16 · #20 · #20HD · #23
- Accessories
- Backshells · shrink boots · strain relief · caps
2M is not MIL-DTL-38999 qualified product. The manufacturer's own wording is that 2M805 "meets D38999 requirements at half the size and weight" and that 2M Hermetic "meets or exceeds most of the environmental and performance requirements of MIL-DTL-38999". Meeting the requirements and being qualified to the specification are two different things. Where a drawing calls out D38999, 2M cannot be substituted — in that case we will point you to the D38999 families.
Coupling
The last digit sets the coupling method
2M801, 2M803, 2M804 and 2M805 differ not in size but in how the connector locks.
2M805
Tri-start ACME thread
Anti-decoupling ratchet and ground spring. For military airframes and avionics boxes, and quick to mate.
2M804
Push-pull quick disconnect
Breakaway that separates when pulled. For headsets and tactical equipment. Gold plated springs give it its mating life and EMI shielding.
2M803
Quarter-turn bayonet
Fast mating, general purpose, light duty. Not an immersion-rated product (splash proof). Shell-to-shell resistance 50 mΩ.
2M801
Dual-start ACME thread
Sturdier keys and threads, and quick to mate. One and a half turns is full mating.
Beyond these there are hermetic versions (2M Hermetic — see the table below), filtered versions (2M Filters), a right-angle low-profile combination (2M Space Saver — 50% lower plug height than the standard 2M801), and a high-vibration version (2M805 High Vibration).
Family specifications compared — contact count · immersion · EMI · vibration · mating life6 rows · tap to expand
| Item | 2M805 | 2M804 | 2M803 | 2M801 |
|---|---|---|---|---|
| Contact count | 1 ~ 130 | 1 ~ 85 | 1 ~ 55 | 1 ~ 130 |
| Mating method | Tri-start thread | Push-pull quick disconnect | Quarter-turn locking bayonet | Thread · full mating in 1½ turns |
| Immersion (mated) | MIL-STD-810 Method 512 · 1 m / 1 hour | MIL-STD-810 Method 512 · 1 m / 1 hour | Splash proof | MIL-STD-810 Method 512 · 1 m / 1 hour |
| EMI shielding | Excellent | Excellent | Fair | Very Good |
| Vibration and shock | Random 43.9 g · sine 60 g · shock 300 g | Random 37 g · shock 300 g | Random 37 g · shock 300 g | Random 43.9 g · sine 60 g · shock 300 g |
| Mating life | 500 cycles | 2,000 cycles | Aluminum 1,000 cycles · stainless 2,000 cycles | -16 plug 2,000 cycles · -26 plug 500 cycles |
Contact ratings are the same across the four families — size #12 23 A / 1800 VAC · #16 13 A / 1800 VAC · #20 7.5 A / 1000 VAC · #23 5 A / 750 VAC. Mating life is shortest on 2M805 and longest on 2M804, so the choice depends on whether the connector is mated and unmated often or mated once and left.
Hermetic receptacles — ordering codes by family4 rows · tap to expand
| Family | Series code | Shell style | Service class | Keying |
|---|---|---|---|---|
| 2M805 | 2M805-006 | -02 square flange · -03 weld mount · -07 rear panel jam nut | Z1 · ZL | A · B · C · D |
| 2M804 | 2M804-006 | -00 front panel jam nut · -07 rear panel jam nut | Z1 · ZL | A · B · C · D |
| 2M803 | 2M803-006 | -02 flange mount · -07 jam nut | Z1 · ZL | N · X · Y · Z |
| 2M801 | 2M801-012 | -02 flange mount · -03 weld mount · -07 jam nut | Z1 · ZL · ZB | A · B · C · D · E · F |
The part number structure has the same six segments as the standard product — series · shell style · service class · shell size-insert arrangement · contact · keying (example: 2M805-006 -07 Z1 12-26 C A). Insert arrangements use the same table as the standard product, so they can be looked up directly in the [Insert arrangements] section below. Shells are stainless steel only (Z1 passivated · ZL electrolytic nickel, with ZB olive drab cadmium on 2M801 alone), and the weld mount -03 comes only in Z1. Contacts are pins only across all four families — P solder cup · C PC tail · H solder cup (no interfacial seal) · Y PC tail (no interfacial seal). Keying angles are the same as the standard product. Shell sizes cover the same range as the standard product, with one exception: 2M803 shell size 15 has no flange mount and comes only as a jam nut (-07). Panel thickness is 0.100″ (2.54 mm) maximum across all four families.
The hermetic ordering guide in the catalog prints the heading of segment ② as "SHELL SIZE", while the standard ordering guide calls the same position "SHELL STYLE" and fills it with mount types (square flange, jam nut and so on). Shell size sits separately in segment ④ — noted here so the two catalog pages do not confuse you when read side by side.
Hermetic PC tail contacts — diameters for board hole design4 rows · tap to expand
| Contact sizes | PC tail diameter (inches) | As also printed in the catalog (millimeters) |
|---|---|---|
| #23 | .018 / .022 | 0.46 / 0.56 |
| #20 · #20HD | .025 / .027 or .024 / .028 — see below | 0.64 / 0.69 |
| #16 | .060 / .064 | 1.52 / 1.63 |
| #12 | .092 / .096 | 2.34 / 2.44 |
Because hermetic contacts are non-removable, these diameters are the basis for board hole and pad design. The values were cross-checked across all nine hermetic dimension pages (p.85 to 87 · 89 · 90 · 92 · 94 to 96) and are the same for all four families and every mount type.
Only the #20 · #20HD row varies within the catalog — five pages (p.86 · 89 · 90 · 92 · 95) print .025 / .027 while four pages (p.85 · 87 · 94 · 96) print .024 / .028. The millimeter figure is 0.64 / 0.69 on all nine pages, which matches the conversion of .025 / .027 (.024 / .028 converts to 0.61 / 0.71). The catalog alone does not settle which is authoritative, so both are reproduced — if you are designing a board we will confirm it per P/N.
The millimeter value for #16 also varies: three pages (p.85 · 86 · 87) print 1.521 and the other six print 1.52 (0.060″ = 1.524 mm).
The manufacturer classifies 2M801 as legacyDetails · tap to expand
The manufacturer places 2M801 in the legacy category and recommends its successor, 2M805. That does not make it discontinued, and the catalog states plainly that 2M801 is the right choice where compatibility or interoperability with existing equipment and cabling has to be preserved. For a new design, consider 2M805; to match existing assets, consider 2M801. Tell us which situation you are in and we will work through it with you.
Hermetic versions have different specifications from the standard productDetails · tap to expand
A receptacle-only version for positions that have to separate pressure or gas across a panel.
CAUTIONThe standard 2M specification tables (the performance and materials section) do not apply to hermetic versions — the catalog states this in a footnote on every specification page.
CAUTIONAn interfacial seal is not included by default — tell us with the P/N if you need one and we will confirm availability.
CAUTIONThe catalog gives two figures for the helium leak rate — we will confirm which applies per P/N. A glass insulator is fused into a stainless steel shell to seal it, and every unit ships after 100% leak testing. The shell is low profile so it protrudes less from the box, it has a shell standoff for PCB washout, and the contacts are non-removable PC tails or solder cups. The two leak rate figures are 1×10⁻⁷ cc/sec in the overview (p.83) and 1×10⁻⁸ cc/sec on all four family ordering guides (p.84 · 88 · 91 · 93). The contact material likewise reads "nickel iron alloy" in the overview and "iron alloy" in the ordering guides.
Size & Weight
How small it is
A comparison the manufacturer published with the equivalent D38999 Series III placed alongside.
2M805 — weight comparison (catalog p.4)8 rows · tap to expand
| 2M805 arrangement | Contacts | 2M805 weight | Equivalent D38999 | D38999 aluminum | Weight saving |
|---|---|---|---|---|---|
| 8-7 | 7 × #23 | 13.4 | 9-35 (6 × #20) | 26.3 | 49% |
| 10-13 | 13 × #23 | 23.0 | 11-35 (13 × #22D) | 35.7 | 36% |
| 11-19 | 19 × #23 | 26.4 | 13-35 (19 × #22D) | 50.7 | 48% |
| 12-26 | 26 × #23 | 29.4 | 17-26 (26 × #20) | 58.5 | 50% |
| 15-37 | 37 × #23 | 42.7 | 15-35 (37 × #22D) | 72.1 | 41% |
| 18-55 | 55 × #23 | 59.6 | 17-35 (55 × #22D) | 81.6 | 27% |
| 19-85 | 85 × #23 | 59.8 | 21-35 (85 × #22D) | 119.7 | 50% |
| 23-130 | 130 × #23 | 85.5 | 25-35 (128 × #22D) | 159.3 | 46% |
Maximum plug diameter runs 17.96 ~ 40.06 mm, which is 7 ~ 29% smaller than the equivalent D38999 (21.81 ~ 47.63 mm), and jam nut receptacle diameter runs 19.69 ~ 43.69 mm, 20 ~ 39% smaller. Against a D38999 composite shell the weight saving is 9 ~ 53%. Weights are in grams.
2M801 — weight comparison (catalog p.5)7 rows · tap to expand
| 2M801 arrangement | Contacts | 2M801 weight | Equivalent D38999 | D38999 aluminum | Weight saving |
|---|---|---|---|---|---|
| 5-3 | 3 × #23 | 7.9 | 9-98 (3 contacts) | 25.3 | 69% |
| 6-7 | 7 × #23 | 9.8 | 9-35 (6 contacts) | 26.3 | 63% |
| 9-19 | 19 × #23 | 18.8 | 13-35 (22 contacts) | 50.7 | 63% |
| 13-37 | 37 × #23 | 36.0 | 15-35 (37 contacts) | 72.1 | 50% |
| 16-55 | 55 × #23 | 49.8 | 17-35 (55 contacts) | 81.6 | 39% |
| 17-85 | 85 × #23 | 54.3 | 21-35 (79 contacts) | 119.7 | 55% |
| 21-130 | 130 × #23 | 68.7 | 25-35 (128 contacts) | 159.3 | 57% |
Cable plug diameter runs 13.72 ~ 39.37 mm, which is 12 ~ 37% smaller than the equivalent D38999 (21.82 ~ 48.01 mm), and jam nut receptacle diameter runs 14.61 ~ 41.28 mm, 28 ~ 52% smaller. Weights are in grams, and both tables are for a mated pair of plug and jam nut receptacle with contacts included.
This table compares size and weight; it is not a table for deciding whether one can replace the other. The arrangements set side by side differ in contact size to begin with — 2M805 is #23 while the D38999 opposite it is #20 and #22D, so the current ratings are not the same. Some rows do not match exactly in contact count either (2M805 8-7 has 7 contacts, D38999 9-35 has 6). Where a drawing calls out D38999, it cannot be substituted even if the size fits.
Performance Spec
Performance and materials specifications
Values the manufacturer publishes together with the test method numbers. They can be used as they stand for specification compliance review or for setting incoming inspection criteria.
Materials (catalog p.21)9 rows · tap to expand
| Part | Material |
|---|---|
| Aluminum shell · barrel · coupling nut | Aluminum alloy 6061-T6 |
| Stainless shell · barrel · coupling nut | Passivated stainless steel, 200 °C |
| Front and rear inserts | Polyphenylene sulfide (PPS) |
| Contact retention clip | Beryllium copper, heat treated |
| Grommet · peripheral seal · interfacial seal | Fluorosilicone rubber |
| Contacts | Gold plated copper alloy |
| Socket contact hood | Passivated stainless steel |
| Adhesives | Various epoxies and RTV |
| Potting compound (PCB and solder cup versions) | High-strength epoxy |
Dielectric withstanding voltage (DWV) — catalog p.224 rows · tap to expand
| Contact sizes | Sea level | Altitude 40,000 feet |
|---|---|---|
| #23 | 750 V | 100 V |
| #20HD | 750 V | 150 V |
| #16 | 1800 V | 1000 V |
| #12 | 1800 V | 1000 V |
EIA-364-20, AC RMS 60 Hz, held for one minute. There must be no breakdown or flashover. Sea level values apply both unmated and mated; altitude values are for the mated condition.
This item carries two different values within the manufacturer's own documentation — the summary table (catalog p.21) gives #20HD 1000 V at sea level and 400 V at altitude for #23 and #20HD, and it also has a #20 row (1000 V at sea level · 400 V at altitude) that the detailed table does not. Checking the separate specification document the catalog points to as the governing one (2M Series Performance Specifications) does not settle it either, because both values appear within that same document. We will confirm the applicable value with the manufacturer per P/N.
Contact retention and separation force (catalog p.25)5 rows · tap to expand
| Contact sizes | Retention min | Separation force min |
|---|---|---|
| #23 | 10 lb (45 N) | 0.5 oz (0.14 N) |
| #20 | 15 lb (67 N) | 0.7 oz (0.19 N) |
| #20HD | 10 lb (45 N) | — |
| #16 | 25 lb (111 N) | 2.0 oz (0.56 N) |
| #12 | 25 lb (111 N) | 3.0 oz (0.83 N) |
Retention is per EIA-364-29 and separation force per SAE AS39029. The catalog does not give a separation force for #20HD. Insert retention is 100 lb minimum across every shell size in all four families (EIA-365-35, p.26).
Shell-to-shell voltage drop (catalog p.23)4 rows · tap to expand
| Family | Initial | After 48 hours salt spray |
|---|---|---|
| 2M801 | 2.5 | 2.5 |
| 2M803 | 100 | 200 |
| 2M804 | 2 | 4 |
| 2M805 | 2 | 2 |
The maximum voltage drop across a mated pair, tested per EIA-364-83 (electroless nickel plated connectors).
The catalog gives no unit on this table, so only the numbers are reproduced.
Contact resistance and current — by wire size8 rows · tap to expand
| Wire size | Test current | Max voltage drop | Low-level contact resistance max |
|---|---|---|---|
| #12 | 23 A | 42 mV | — |
| #14 | 17 A | 40 mV | — |
| #16 | 13 A | 49 mV | 5 mΩ |
| #20 | 7.5 A | 55 mV | 9 mΩ |
| #22 | 5 A | 73 mV | 15 mΩ |
| #24 | 3 A | 45 mV | 20 mΩ |
| #26 | 2 A | 52 mV | 31 mΩ |
| #28 | 1.5 A | 54 mV | 50 mΩ |
Contact resistance is per SAE AS39029 Table V, tested per EIA-364-06 (silver plated copper wire, +25 °C). Low-level contact resistance is per EIA-364-23 (test current at or below 100 mA, open circuit voltage at or below 20 mV), and the catalog gives no values for #12 or #14.
The axis of this table is wire size, not contact size. Current capacity by contact size is #12 23 A · #16 13 A · #20 7.5 A · #23 5 A (EIA-364-70 Method 1).
Shielding effectiveness — minimum attenuation in dB by frequency10 rows · tap to expand
| Frequency | 2M801 | 2M803 | 2M804 | 2M805 |
|---|---|---|---|---|
| 100 MHz | 75 | 60 | 90 | 90 |
| 200 MHz | 70 | 55 | 88 | 88 |
| 300 MHz | 65 | 55 | 88 | 88 |
| 400 MHz | 63 | 50 | 87 | 87 |
| 800 MHz | 58 | 45 | 85 | 85 |
| 1000 MHz | 55 | 40 | 85 | 85 |
| 1 GHz | 55 | — | 55 | 85 |
| 3 GHz | 50 | — | 50 | 69 |
| 5 GHz | 45 | — | 45 | 66 |
| 19 GHz | 40 | — | 40 | 65 |
The low band (100 MHz to 1000 MHz) is tested per EIA-364-21 and the high band per EIA-364-66, both for electroless nickel plated connectors. The catalog groups 2M804 with 2M805 in the low-band table and 2M801 with 2M804 in the high-band table into single cells, so the same value has been placed in each family's column. There are no high-band values for 2M803.
The high-band table is titled 1 GHz to 10 GHz, yet its last row is printed as 19 GHz — reproduced as printed.
Mechanical tests — vibration, shock and durability10 rows · tap to expand
| Item | Requirement · condition | Test method |
|---|---|---|
| Vibration (sine) | 2M801 · 2M805 60 g · 2M803 · 2M804 30 g / 10-2000-10 Hz, 12 sweep cycles per axis · 20 minutes | MIL-STD-202 Method 204 Condition G |
| Vibration (random) | 2M801 · 2M805 43.9 g RMS · 2M803 · 2M804 37.80 g RMS / 50 ~ 2,000 Hz | EIA-364-28 Condition V Letter I · test current 100 mA |
| Gunfire vibration | No discontinuity longer than 1 μs · no cracking, breakage or loosening of parts · the plug must not come out of the receptacle | MIL-STD-810F Method 519.5 |
| Mechanical shock | Same requirement as the vibration items above | EIA-364-27 Condition D · 300 G half sine 3 ms · 3 axes |
| Mechanical durability (room temperature) | After 2,000 mating and unmating cycles (where applicable), contact resistance, insulation resistance, shell-to-shell resistance, DWV and mating force are maintained | EIA-364-09 |
| Insert retention | 100 lb minimum across every shell size in all four families | EIA-365-35 |
| Impact (drop) | No loss of function · contact resistance, insulation resistance and water sealing maintained | EIA-364-42 · 1 m · 8 drops |
| Solderability (PC tail contacts) | 95% solder coverage · smooth, even surface | EIA-364-52 Category 3 · 8 hours steam aging · 245 °C for 4 to 5 seconds · inspected at 10x magnification |
| Resistance to soldering heat | No damage to the connector · insulation resistance and water sealing maintained | EIA-364-56 · 260 °C for 10 seconds (PC tail) |
| Magnetic permeability | 2 μ max | EIA-364-54 |
For random vibration the detailed table (p.24) gives 37.80 g RMS for 2M803 and 2M804, while the selection table (p.3) used by the comparison in the family section gives 37 g for the same item. Mating life differs by family, so refer to the comparison in the family section — the 2,000 cycles here carries the qualifier "where applicable".
Environmental tests — temperature, immersion, humidity and salt spray11 rows · tap to expand
| Item | Requirement · condition | Test method |
|---|---|---|
| Operating temperature | -65 ~ +175 °C | — |
| Immersion (mated) | No evidence of water ingress in the mated connector · insulation resistance ≥100 Ω | MIL-STD-810F Method 512.4 · 1 m depth · 1 hour |
| Immersion (open-face panel receptacle) | Non-removable PCB or solder cup contacts with water-block potting. After thermal shock, helium leak rate at or below 1×10⁻⁴ cc/sec at one atmosphere differential | EIA-365-02 · 3 thermal shock cycles -57 ~ +71 °C · 75 minute dwell · 5 minute transfer |
| Humidity (cyclic, moisture resistance) | Insulation resistance at or above 100 MΩ during the final cycle · contact resistance, shell-to-shell resistance and DWV maintained after recovery | EIA-364-31 Condition B Method III · 80 ~ 98% RH · 10 cycles (10 days) · +25 ~ +65 °C · 24 hour recovery |
| Humidity (21 day extended) | Insulation resistance at or above 100 MΩ after drying · contact resistance, shell-to-shell resistance, DWV and mating force maintained | EIA-364-31 Condition C Method II · 90 ~ 95% RH · 40 °C · 100 V DC applied during the test |
| Thermal shock | No mechanical damage or loosening of parts · contact resistance, DWV, insulation resistance and shell-to-shell resistance maintained afterwards | EIA-364-32 Test Condition IV · 5 cycles · -65 °C 30 minutes ↔ +150 °C 30 minutes |
| Salt spray (corrosion) | No exposure of base metal · DWV and contact resistance maintained after the test | EIA-364-26 · 5% salt solution · 35 °C · unmated — finish C 48 hours · M 48 hours · MT 500 hours · NF 500 hours · ZNU 500 hours |
| Sand and dust | Must withstand blowing sand and dust while mated | MIL-STD-810F Method 510.4 |
| Fungus | Materials must be inert to fungus | MIL-STD-810F Method 508.5 |
| Fluid immersion | No visible damage after immersion in various fuels and oils · coupling torque and DWV maintained | EIA-364-10 · unmated |
| Altitude immersion | No evidence of moisture at the connector interface or contacts · DWV maintained | EIA-364-03 |
Salt spray duration splits between 48 hours and 500 hours depending on the finish code — for coastal or naval environments, check the service class in the P/N.
The insulation resistance for mated immersion reads "≥100Ω" in the catalog. It looks out of line with the other items, which are in MΩ, but it is reproduced as printed.
2M804 separation force — push-pull breakaway9 rows · tap to expand
| Insert arrangements | Separation force (pounds) |
|---|---|
| 5-3 | 10.6 |
| 6-4 | 10.8 |
| 6-7 | 11.4 |
| 7-10 | 12.0 |
| 8-13 | 12.6 |
| 9-19 | 13.8 |
| 10-26 | 15.2 |
| 12-37 | 17.4 |
| 14-55 | 21.0 |
2M804 is a push-pull that separates when pulled, so it is given a separation force instead of a coupling torque. The arrangement numbers are 2M804 numbers — the same number means a different arrangement in another family, so read this together with the insert arrangements section.
These specifications are for the standard design. The catalog states at the foot of every specification page that "Filter and Hermetic designs have different specifications", so they do not carry over to hermetic or filtered versions. If you need those, ask us with the P/N and we will confirm them separately.
Part Number
Breaking down a 2M801 part number
The number on the drawing alone is enough to tell what form the part takes. 2M801-007-16M10-5PA is used here as the example.
Part number structure — the same across all four families6 segments · tap to expand
- 2M801-007-16M10-5PA① Series — connector form — Plug with an integral backshell
- 2M801-007-16M10-5PA② Shell style — Anti-decoupling
- 2M801-007-16M10-5PA③ Service class — shell material and finish — Electroless nickel
- 2M801-007-16M10-5PA④ Shell size and insert arrangement — Shell size 10, arrangement 5
- 2M801-007-16M10-5PA⑤ Contacts — Pin
- 2M801-007-16M10-5PA⑥ Keying — A (A 150° · B 210°)
2M805 and 2M804 add one further optional suffix segment here. The catalog ordering guide carries no code table for that segment, so this page does not assert what it means.
① Series code — different in each family4 rows · tap to expand
| Family | Crimp (plug · receptacle) | PCB · solder | Hermetic |
|---|---|---|---|
| 2M805 | -001 banding platform plug · -002 accessory thread plug · -003 banding platform receptacle · -004 accessory thread receptacle | -005 epoxy potted · -017 open-face immersion · -067 PCB strain relief standoff flange · -011 right-angle PCB | -006 |
| 2M804 | -001 integral backshell plug · -002 accessory thread plug · -003 banding platform receptacle · -004 accessory thread receptacle | -005 epoxy potted · -020 open-face immersion · -025 PCB strain relief standoff flange · -009 solder cup/PCB plug · -021 open-face immersion plug | -006 |
| 2M803 | -001 integral backshell plug · -002 accessory thread plug · -003 integral backshell receptacle · -004 accessory thread receptacle | -005 epoxy potted · -015 open-face immersion | -006 |
| 2M801 | -007 integral backshell plug · -008 accessory thread plug · -009 banding platform receptacle · -010 accessory thread receptacle | -011 epoxy potted · -033 open-face immersion · -075 PCB strain relief standoff flange · -023 right-angle PCB | -012 |
"Open-face immersion" is a specially sealed item for cases where immersion is required while unmated, and every unit goes through leak testing. The same -005 means a different part in a different family, so the family number has to come with it to be exact. The hermetic code is -012 on 2M801 alone and -006 on the other three families — see the family section for the detail.
② Shell style — different in each family4 rows · tap to expand
| Family | Plug | Receptacle | PCB · solder |
|---|---|---|---|
| 2M805 | -16 self-locking ratchet | -01 in-line · -02 square flange · -07 jam nut | -02 square flange · -07 jam nut (right angle is -07) |
| 2M804 | -06 | -00 front panel jam nut · -01 in-line · -07 rear panel jam nut | -00 front jam nut · -07 rear jam nut (plugs also have -02 rear flange) |
| 2M803 | -06 anti-decoupling | -01 in-line · -02 flange mount · -07 jam nut | -02 flange mount · -07 jam nut |
| 2M801 | -16 anti-decoupling · -26 self-locking ratchet | -01 in-line · -02 square flange · -07 jam nut | -02 square flange · -07 jam nut · -12 non-locking clinch nut · -22 locking clinch nut (right angle is -07) |
Adding -501 to a jam nut part number supplies a hex nut in place of the spanner nut (the same in all four families).
⑥ Keying — the angles match but the letters do not6 rows · tap to expand
| Angle (A° / B°) | 2M805 · 2M804 | 2M803 | 2M801 |
|---|---|---|---|
| 150° / 210° | A | N | A |
| 75° / 210° | B | X | B |
| 95° / 230° | C | Y | C |
| 140° / 275° | D | Z | D |
| 75° / 275° | — | — | E |
| 95° / 210° | — | — | F |
The same angle carries a different letter in a different family. 2M803 alone uses N · X · Y · Z, and 2M801 has E and F in addition. Copying a letter across from another family's drawing gets it wrong, so take care. On 2M804 this segment is left blank when only the master key is used.
③ Service class · ⑤ Contact — the same in all four families4 rows · tap to expand
| Segment | Codes | What they mean |
|---|---|---|
| Service class (aluminum) | C · M · NF · MT · ZN · ZNU · BEN | Anodize (non-conductive) · electroless nickel · olive drab cadmium · Durmalon (Ni PTFE) · olive drab zinc nickel · black zinc nickel · black electroless nickel |
| Service class (stainless) | Z1 · ZL | Passivated · electrolytic nickel |
| Contacts (crimp) | P · S · A · B | Pin · socket · less pins · less sockets |
| Contacts (PCB · solder) | P · S · E · F | Pin PCB · socket PCB · pin solder cup · socket solder cup |
Every finish except cadmium (NF) is RoHS compliant. Shell size and insert arrangement (④) can be looked up by contact count in the tables in the [Insert arrangements] section below.
A partial number is fine. Give us the series and the shell size and we will confirm and fill in the rest.
Insert Arrangements
Finding an arrangement number by contact count
If you know the contact size and the number of contacts you need, the arrangement number in each of the four families follows directly. The same table works in reverse to identify an arrangement number from a drawing.
Rating and applicable wire by contact size5 rows · tap to expand
| Contact sizes | Max current | Test voltage (DWV) | Applicable wire |
|---|---|---|---|
| #23 | 5 A | 750 VAC | #22 ~ #28 AWG |
| #20HD | 7.5 A | 1000 VAC | #20 ~ #24 AWG |
| #20 | 7.5 A | 1000 VAC | #20 ~ #24 AWG |
| #16 | 13 A | 1800 VAC | #16 ~ #20 AWG |
| #12 | 23 A | 1800 VAC | #12 ~ #14 AWG |
The catalog gives #20 and #20HD the same rating. Single-size arrangements use only #20HD, and plain #20 appears only in the two mixed arrangements (#23 + #20).
The #20 rating reads 7.5 A consistently in the contact table (p.100) and in arrangement detail 9-201 (p.7), but 8-200 (p.7) alone is printed as 7 A — if you are using that arrangement we will confirm it per P/N.
Single-size arrangements — one contact size throughout35 rows · tap to expand
| Contact sizes | Contacts | 2M801 | 2M803 | 2M804 | 2M805 |
|---|---|---|---|---|---|
| #23 | 3 | 5-3 | 5-3 | 5-3 | — |
| #23 | 4 | 6-4 | 6-4 | 6-4 | 8-4 |
| #23 | 6 | 6-6 | 6-6 | 6-6 | 8-6 |
| #23 | 7 | 6-7 | 6-7 | 6-7 | 8-7 |
| #23 | 10 | 7-10 | 7-10 | 7-10 | 9-10 |
| #23 | 13 | 8-13 | 8-13 | 8-13 | 10-13 |
| #23 | 19 | 9-19 | 9-19 | 9-19 | 11-19 |
| #23 | 26 | 10-26 | 10-26 | 10-26 | 12-26 |
| #23 | 37 | 13-37 | 12-37 | 12-37 | 15-37 |
| #23 | 55 | 16-55 | 14-55 | 14-55 | 18-55 |
| #23 | 85 | 17-85 | 15-85 | 15-85 | 19-85 |
| #23 | 130 | 21-130 | — | — | 23-130 |
| #20HD | 3 | 6-23 | 6-23 | 6-23 | 8-23 |
| #20HD | 5 | 7-25 | 7-25 | 7-25 | 9-25 |
| #20HD | 8 | 8-28 | 8-28 | 8-28 | 10-28 |
| #20HD | 10 | 9-210 | 9-210 | 9-210 | 11-210 |
| #20HD | 20 | 13-220 | 12-220 | 12-220 | 15-220 |
| #20HD | 35 | 16-235 | 14-235 | 14-235 | 18-235 |
| #20HD | 41 | 17-241* | — | — | 19-241* |
| #20HD | 69 | 21-269 | — | — | 23-269 |
| #16 | 1 | 6-1* | 6-1* | 6-1* | 8-1* |
| #16 | 2 | 8-2 | 8-2 | 8-2 | 10-2 |
| #16 | 4 | 9-4 | 9-4 | 9-4 | 11-4 |
| #16 | 5 | 10-5 | 10-5 | 10-5 | 12-5 |
| #16 | 7 | 13-7 | 12-7 | 12-7 | 15-7 |
| #16 | 12 | 16-12 | 14-12 | 14-12 | 18-12 |
| #16 | 14 | 17-14* | 15-14 | 15-14 | 19-14* |
| #16 | 22 | 21-22* | — | — | 23-22* |
| #12 | 1 | 7-1* | 7-1* | 7-1* | 9-1* |
| #12 | 2 | 10-2 | 10-2 | 10-2 | 12-2 |
| #12 | 2 | 13-2 | 12-2 | 12-2 | 15-2 |
| #12 | 3 | 13-3* | 12-3* | 12-3* | 15-3* |
| #12 | 5 | 16-5 | 14-5 | 14-5 | 18-5 |
| #12 | 7 | 17-7 | 15-7 | 15-7 | 19-7 |
| #12 | 12 | 21-12 | — | — | 23-12 |
"—" means that arrangement does not exist in that family (NA in the catalog). #12 has two 2-contact arrangements, differing in shell size.
Mixed-size (combo) arrangements — two contact sizes in one connector8 rows · tap to expand
| Make-up | 2M801 | 2M803 | 2M804 | 2M805 |
|---|---|---|---|---|
| #23 × 4 + #20 × 2 | 8-200* | 8-200* | 8-200* | 10-200* |
| #23 × 8 + #20 × 2 | 9-201 | 9-201 | 9-201 | 11-201 |
| #23 × 4 + #16 × 2 | 9-200 | 9-200 | 9-200 | 11-200 |
| #23 × 8 + #16 × 2 | 10-202* | 10-202* | 10-202* | 12-202* |
| #23 × 4 + #12 × 2 | 10-201 | 10-201 | 10-201 | 12-201 |
| #23 × 6 + #12 × 2 | 13-200* | 12-200 | 12-200 | 15-200* |
| #23 × 10 + #12 × 2 | 13-201 | 12-201 | 12-201 | 15-201 |
| #23 × 12 + #12 × 1 | 10-200* | 10-200* | 10-200* | 12-200* |
These arrangements carry power and signal in one connector. The larger contacts (#12 · #16 · #20) take the power and #23 takes the signal.
An arrangement number on its own does not pin the part down — the family number has to come with it. The same number is a different part in a different family. "10-2" is #12 × 2 in 2M801, 2M803 and 2M804 but #16 × 2 in 2M805, and "10-200" is #23 × 12 + #12 × 1 in the 2M801 family but #23 × 4 + #20 × 2 in 2M805. The * in the tables is the catalog footnote "Not tooled for every insert pattern", meaning not every insert pattern has been tooled. For those arrangements we confirm whether the part can actually be produced, per P/N, before replying.
Contacts & Tools
Contacts, tooling and tightening torque
Contacts are ordered as a separate item from the connector. The tooling and torque values needed for assembly are set out here as well.
Crimp contact P/N (catalog p.100)12 rows · tap to expand
| Contact sizes | Type | Rating | Applicable wire | P/N | Color bands |
|---|---|---|---|---|---|
| #23 | Pin | 5 A | #22 ~ #28 AWG | 2M809-001 | — |
| #23 | Pin | 5 A | #26 ~ #30 AWG | 2M809-042 * | Blue |
| #23 | Socket | 5 A | #22 ~ #28 AWG | 2M809-002 | — |
| #23 | Socket | 5 A | #26 ~ #30 AWG | 2M809-043 * | Blue |
| #20HD | Pin | 7.5 A | #20 ~ #24 AWG | 2M809-204 | — |
| #20HD | Socket | 7.5 A | #20 ~ #24 AWG | 2M809-205 | — |
| #20 | Pin | 7.5 A | #20 ~ #24 AWG | M39029/58-363 | Orange · blue · orange |
| #20 | Socket | 7.5 A | #20 ~ #24 AWG | M39029/57-357 | Orange · green · violet |
| #16 | Pin | 13 A | #16 ~ #20 AWG | M39029/58-364 | Orange · blue · orange |
| #16 | Socket | 13 A | #16 ~ #20 AWG | M39029/57-358 | Orange · green · gray |
| #12 | Pin | 23 A | #12 ~ #14 AWG | M39029/58-365 | Orange · blue · green |
| #12 | Socket | 23 A | #12 ~ #14 AWG | M39029/57-359 | Orange · green · white |
The catalog designates #20 · #16 · #12 by military specification number (M39029 slash sheets) and #23 · #20HD by Amphenol's own number (2M809-…). That the numbering systems differ is itself information, so it is reproduced as printed — but being designated by an M39029 number and that loose part being QPL listed are two different statements, and the catalog goes only as far as the number. The * marks a special order item.
Crimping, insertion and removal tools (catalog p.100)5 rows · tap to expand
| Contact sizes | Crimper | Positioner | Insertion · removal |
|---|---|---|---|
| #23 | M22520/2-01 | K1461-1 (Daniels) | DAK225-22 (insertion only) · 2M809-23R (removal only) |
| #20HD | M22520/2-01 | 2M809-206 | 2M809-20HDR (removal only) |
| #20 | M22520/1-01 | M22520/1-04 | M81969/14-10 |
| #16 | M22520/1-01 | M22520/1-04 | M81969/14-03 |
| #12 | M22520/1-01 | M22520/1-04 | M81969/14-04 |
K1461-1 and DAK225-22 are Daniels Manufacturing part numbers. The spanner and holding tools for tightening jam nuts carry a different part number for each shell size and family (the 2M600-… range), so send us the connector P/N and we will confirm the right tool.
Grommet sealing plugs (catalog p.103)4 rows · tap to expand
| Contact sizes | Color | Amphenol P/N | Military P/N |
|---|---|---|---|
| #23 | Black | 2M809-155 | MS27488-22-2 |
| #20 | Red | 2M859-012 | MS27488-20-2 |
| #16 | Green | 2M859-013 | MS27488-16-2 |
| #12 | Orange | 2M859-014 | MS27488-12-2 |
These plug the unused contact cavities so the seal holds. Leaving a cavity open means there is no environmental seal.
Tightening torque — coupling, jam nut and backshell10 rows · tap to expand
| Shell size (2M801 · 2M803) | Shell size (2M805) | Coupling | Jam nut | Backshell |
|---|---|---|---|---|
| 5 | — | 2.8 ~ 4.0 N·m | 2.2 ~ 2.8 N·m | 1.5 ~ 1.9 N·m |
| 6 | 8 | 4.0 ~ 4.5 N·m | 2.2 ~ 2.8 N·m | 2.0 ~ 2.5 N·m |
| 7 | 9 | 4.0 ~ 4.5 N·m | 2.2 ~ 2.8 N·m | 3.4 ~ 4.5 N·m |
| 8 | 10 | 4.5 ~ 5.7 N·m | 2.2 ~ 2.8 N·m | 3.4 ~ 4.5 N·m |
| 9 | 11 | 4.5 ~ 5.7 N·m | 2.2 ~ 2.8 N·m | 4.0 ~ 5.1 N·m |
| 10 | 12 | 5.7 ~ 6.8 N·m | 2.8 ~ 3.3 N·m | 4.0 ~ 5.1 N·m |
| 12 · 13 | 15 | 5.7 ~ 6.8 N·m | 2.8 ~ 3.3 N·m | 4.0 ~ 5.1 N·m |
| 14 · 16 | 18 | 6.2 ~ 7.3 N·m | 2.8 ~ 3.3 N·m | 4.0 ~ 5.1 N·m |
| 15 · 17 | 19 | 6.2 ~ 7.3 N·m | 2.8 ~ 3.3 N·m | 4.0 ~ 5.1 N·m |
| 21 | 23 | 6.2 ~ 7.3 N·m | 2.8 ~ 3.3 N·m | 4.0 ~ 5.1 N·m |
Converted to inch-pounds these fall in the ranges 25 ~ 65 in-lb for coupling, 20 ~ 30 in-lb for the jam nut, and 13 ~ 45 in-lb for the backshell (the catalog carries both units). 2M804 is a push-pull with no coupling torque, so it does not appear in this table.
Coupling torque limit — the values differ from the tightening torque on p.1008 rows · tap to expand
| 2M801 shell size | 2M805 shell size | Inch-pounds |
|---|---|---|
| 5 · 6 · 7 | 8 · 9 | 8 |
| 8 · 9 | 10 · 11 | 9 |
| 10 | 12 | 12 |
| 12 · 13 | 15 | 16 |
| 14 · 15 | 18 | 28 |
| 16 · 17 | 19 | 24 |
| 21 | — | 32 |
| — | 23 | 36 |
The catalog has two torque tables and their values differ. The table just above (p.100) gives a minimum and maximum tightening torque, while this one (p.25) gives a single limit: "the coupling torque of threaded connectors shall not exceed the following values". The catalog does not say which to use as the assembly instruction, so this page does not assert one — send us the P/N and we will confirm. 2M803 and 2M804 are not in this table.
Accessories
Backshells, shrink boots and caps
There is a separate accessory line that serves every 2M connector family. These are ordered as separate items from the connector.
Part number ranges (catalog p.99 to p.124)12 rows · tap to expand
| Item | Part number range | Forms |
|---|---|---|
| Environmental backshell | 2M370MS038 · 2M370MS037 · 2M370MB038 · 2M370MA038 | Straight (rotatable coupling) · straight (direct) · 45° · 90° |
| EMI backshell | 2M380MS137 · 2M380MS135 · 2M380MB137 · 2M380MA137 | Straight (rotatable coupling) · straight (direct) · 45° · 90° |
| Environmental EMI backshell | 2M390MS077 · 2M390MS076 · 2M390MB077 · 2M390MA077 | Straight (rotatable coupling) · straight (direct) · 45° · 90° |
| Shorting cap backshell | 2M340MS026 | Shorts and protects an unused receptacle. Six attachment styles (nylon rope · stainless wire rope · stainless chain · slip knot · none) |
| Strain relief clamp | 2M620MS064 · 2M620MS065 | Cable strain relief |
| Micro band adapter | 2M440MS135 · 2M440MK135 · 2M440ML135 · 2M440MS134 | Three threaded versions · one low profile |
| Shrink boots | 2M809S060 · 2M809A060 | Lipped straight · lipped right angle. Boot sizes 1 to 6 |
| Protective cap | 2M667-261 · 262 (2M805) · 2M667-202 · 2M809-198 (2M804) · 2M660-082 · 083 (2M803) · 2M667-217 · 218 (2M801) | Family specific — not interchangeable between families |
| Plug rubber cap | 2M809-083 · 2M809-087 | Common to all families |
| Hex jam nut | 2M809-035 | For receptacles. Three safety wire holes at 120° spacing |
| Flange gasket | 2M809-108 | For flange mount receptacles |
| O-ring | 2M809-054 (2M801) · 2M809-055 (2M804) · conductive versions are 249-003-… | For jam nut receptacles. The part number differs by shell size — four materials (fluorosilicone · EPDM · Cho-Seal 1285 · Cho-Seal 1298) |
ADMTEC keeps 2M shrink boots in Korean stock. Send the connector P/N together with the cable outer diameter and we will confirm the right size.
The 45° and 90° part numbers for EMI backshells differ within the catalog — the ordering information (p.113) gives 2M380MB137 and MA137 while the dimension page (p.114) gives MB138 and MA138. The table above follows the ordering page, and we confirm the P/N before placing an order.
Backshell part number structure — six segments, common to environmental and EMI6 segments · tap to expand
- 2M370MS038-M0705-6N① Part number — backshell type and entry angle — Environmental, straight, rotatable coupling
- 2M370MS038-M0705-6N② Service class — material and finish — Electroless nickel
- 2M370MS038-M0705-6N③ Size code — accessory thread — .4375-28 UNEF-2B
- 2M370MS038-M0705-6N④ Cable entry size — Clamp code 05
- 2M370MS038-M0705-6N⑤ Length — 0.750 inch (in 0.125 inch steps)
- 2M370MS038-M0705-6N⑥ Option — Low-profile compression nut. Left blank, a saddle bar screw clamp
Service class uses the same code system as the connector — aluminum -C · -M · -NF · -MT · -ZN · -ZNU, stainless -Z1 · -ZL. Adapters, clamps, nuts and saddles are aluminum 6061-T6 or 300 series stainless, and the O-rings are silicone rubber.
Connector shell size → backshell size code11 rows · tap to expand
| Accessory thread | Size code | 2M801 | 2M803 | 2M804 | 2M805 |
|---|---|---|---|---|---|
| .2500-32 UNEF-2B | 05 | 5 | 5 | 5 | — |
| .3125-32 UNEF-2B | 06 | 6 | 6 | 6 | — |
| .3750-32 UNEF-2B | 11 | — | — | — | 8 |
| .4375-28 UNEF-2B | 07 | 7 | 7 | 7 | 9 |
| .5000-28 UNEF-2B | 08 | 8 | 8 | 8 | 10 |
| .5625-24 UNEF-2B | 09 | 9 | 9 | 9 | 11 |
| .6250-24 UNEF-2B | 10 | 10 | 10 | 10 | 12 |
| .6875-24 UNEF-2B | 12 | 13 | 12 | 12 | — |
| .7500-20 UNEF-2B | 13 | — | — | — | 15 |
| .9375-20 UNEF-2B | 14 | 16 · 17 | 14 · 15 | 14 · 15 | 18 · 19 |
| 1.1875-18 UNEF-2B | 17 | 21 | — | — | 23 |
Knowing the connector shell size fixes segment ③, the size code, in the backshell part number. Environmental and EMI backshells use the same table.
Flange gasket P/N — by shell size28 rows · tap to expand
| Family | Shell size | Fluorosilicone | Viton® | Conductive fluorosilicone |
|---|---|---|---|---|
| 2M801 | 5 | 2M809-108F11 | 2M809-108V11 | 2M809-108X11 |
| 2M801 | 6 | 2M809-108F12 | 2M809-108V12 | 2M809-108X12 |
| 2M801 | 7 | 2M809-108F13 | 2M809-108V13 | 2M809-108X13 |
| 2M801 | 8 | 2M809-108F14 | 2M809-108V14 | 2M809-108X14 |
| 2M801 | 9 | 2M809-108F16 | 2M809-108V16 | 2M809-108X16 |
| 2M801 | 10 | 2M809-108F15 | 2M809-108V15 | 2M809-108X15 |
| 2M801 | 13 | 2M809-108F17 | 2M809-108V17 | 2M809-108X17 |
| 2M801 | 16 | 2M809-108F18 | 2M809-108V18 | 2M809-108X18 |
| 2M801 | 17 | 2M809-108F19 | 2M809-108V19 | 2M809-108X19 |
| 2M801 | 21 | 2M809-108F43 | 2M809-108V43 | 2M809-108X43 |
| 2M803 | 5 | 2M809-108F31 | 2M809-108V31 | 2M809-108X31 |
| 2M803 | 6 | 2M809-108F32 | 2M809-108V32 | 2M809-108X32 |
| 2M803 | 7 | 2M809-108F33 | 2M809-108V33 | 2M809-108X33 |
| 2M803 | 8 | 2M809-108F34 | 2M809-108V34 | 2M809-108X34 |
| 2M803 | 9 | 2M809-108F35 | 2M809-108V35 | 2M809-108X35 |
| 2M803 | 10 | 2M809-108F36 | 2M809-108V36 | 2M809-108X36 |
| 2M803 | 12 | 2M809-108F37 | 2M809-108V37 | 2M809-108X37 |
| 2M803 | 14 | 2M809-108F38 | 2M809-108V38 | 2M809-108X38 |
| 2M803 | 15 | 2M809-108F39 | 2M809-108V39 | 2M809-108X39 |
| 2M805 | 8 | 2M809-108F20 | 2M809-108V20 | 2M809-108X20 |
| 2M805 | 9 | 2M809-108F21 | 2M809-108V21 | 2M809-108X21 |
| 2M805 | 10 | 2M809-108F22 | 2M809-108V22 | 2M809-108X22 |
| 2M805 | 11 | 2M809-108F23 | 2M809-108V23 | 2M809-108X23 |
| 2M805 | 12 | 2M809-108F24 | 2M809-108V24 | 2M809-108X24 |
| 2M805 | 15 | 2M809-108F25 | 2M809-108V25 | 2M809-108X25 |
| 2M805 | 18 | 2M809-108F26 | 2M809-108V26 | 2M809-108X26 |
| 2M805 | 19 | 2M809-108F27 | 2M809-108V27 | 2M809-108X27 |
| 2M805 | 23 | 2M809-108F28 | 2M809-108V28 | 2M809-108X28 |
The last two digits of the part number are not the shell size — on 2M801, size 9 is F16 and size 10 is F15, so the order is inverted. Do not infer a rule; look it up in this table. The material is set by the third character from the end (F fluorosilicone · V Viton® · X conductive fluorosilicone). Thickness is .032" (0.81 mm) across all three families. 2M804 is a push-pull and has no flange gasket table.
Backshells come in four branches — environmental (sealing), EMI (shielding), environmental EMI (both), and shorting cap — and the right-angle low-profile plug and backshell combination, 2M Python, belongs here as well. Send us the connector P/N, the cable outer diameter, and the entry angle you need, and we will confirm the right part number.
Dimensions
Environmental backshell dimensions
Two segments of the backshell part number govern opposite ends of the part. Segment ③, the size code, governs the front end that mates to the connector — it is the thread that matches the connector shell size, and in the drawing it fixes A thread · B · C on the two straight views. Segment ④, the cable entry size, governs the rear end where the cable comes in — it is the clamp code that matches the cable outer diameter, and it fixes D · E · F · G on the 45° and 90° views, K on the compression nut, and H · J on the saddle clamp. In short, the connector sets the front dimensions and the cable sets the rear ones.
By size code — A thread · B · C11 rows · tap to expand
| Size code | A thread (UNEF-2B) | B max | C max |
|---|---|---|---|
| 05 | .2500-32 | 11.94 mm (.470") | 8.89 mm (.350") |
| 06 | .3125-32 | 13.46 mm (.530") | 10.54 mm (.415") |
| 11 | .3750-32 | 14.48 mm (.570") | 11.68 mm (.465") |
| 07 | .4375-28 | 16.18 mm (.637") | 13.46 mm (.530") |
| 08 | .5000-28 | 17.78 mm (.700") | 15.11 mm (.595") |
| 09 | .5625-24 | 19.25 mm (.758") | 16.51 mm (.650") |
| 10 | .6250-24 | 20.80 mm (.819") | 18.16 mm (.715") |
| 12 | .6875-24 | 22.76 mm (.896") | 19.94 mm (.785") |
| 13 | .7500-20 | 23.62 mm (.930") | 21.08 mm (.830") |
| 14 | .9375-20 | 28.88 mm (1.137") | 25.91 mm (1.020") |
| 17 | 1.1875-18 | 32.51 mm (1.280") | 32.51 mm (1.280") |
B is the maximum outside diameter of the straight rotatable coupling (MS038) and C that of the straight direct version (MS037). The size code follows from the connector shell size — see the cross reference in the accessories section.
Dimensions by cable entry code — D · E · F · G · H · J · K9 rows · tap to expand
| Entry code | Cable sealing diameter (min ~ max) | D max | E max | F max | G max | H ⌀ | J ⌀ | K ⌀ |
|---|---|---|---|---|---|---|---|---|
| 01 | .031" ~ .109" | 15.32 (.603") | 14.67 (.581") | 18.39 (.724") | 17.83 (.702") | 12.60 (.496") | 2.79 (.110") | 10.11 (.398") |
| 02 | .078" ~ .172" | 15.32 (.603") | 14.67 (.581") | 18.39 (.724") | 17.83 (.702") | 14.78 (.582") | 4.32 (.170") | 11.68 (.460") |
| 03 | .140" ~ .234" | 15.32 (.603") | 14.67 (.581") | 18.39 (.724") | 17.83 (.702") | 16.66 (.656") | 5.84 (.230") | 13.28 (.523") |
| 04 | .203" ~ .297" | 15.98 (.629") | 15.42 (.607") | 19.96 (.786") | 19.41 (.764") | 18.44 (.726") | 7.62 (.300") | 14.86 (.585") |
| 05 | .265" ~ .359" | 15.98 (.629") | 15.42 (.607") | 19.96 (.786") | 19.41 (.764") | 22.48 (.885") | 9.14 (.360") | 16.43 (.647") |
| 06 | .328" ~ .422" | 16.64 (.655") | 16.00 (.633") | 21.54 (.848") | 20.98 (.826") | 24.18 (.952") | 10.67 (.420") | 18.03 (.710") |
| 07 | .390" ~ .484" | 16.64 (.655") | 16.00 (.633") | 21.54 (.848") | 20.98 (.826") | 25.86 (1.018") | 12.19 (.480") | 19.63 (.773") |
| 08 | .453" ~ .547" | 17.96 (.707") | 17.40 (.685") | 23.14 (.911") | 22.68 (.889") | 27.53 (1.084") | 13.97 (.550") | 21.21 (.835") |
| 09 | .515" ~ .609" | 17.96 (.707") | 17.40 (.685") | 23.14 (.911") | 22.58 (.889") | 29.16 (1.148") | 15.49 (.610") | 22.76 (.897") |
Values are in millimeters with inches in parentheses. D is the 45° entry, E the 45° entry length, and F and G the width and height of the 90° entry. H, J and K are saddle clamp and compression nut dimensions, with tolerances of H ±0.38 · J ±0.76 · K ±0.38 mm.
Rows 08 and 09 of G max both read .889" yet their millimeter figures differ, 22.68 against 22.58 (.889" = 22.58 mm). Reproduced as printed; the source alone does not settle which is the typo, so if that dimension matters to you we will confirm it per P/N.
Where EMI and environmental EMI differ7 rows · tap to expand
| Item | Environmental 2M370M… | EMI 2M380M… | Environmental EMI 2M390M… |
|---|---|---|---|
| Size 11 · C max | 11.68 (.465") | 11.68 (.465") | 14.48 (.570") |
| Size 17 · B max | 32.51 (1.280") | 35.23 (1.387") | 35.23 (1.387") |
| E max (entries 01 to 03) | 14.67 (.581") | 14.67 (.581") | 14.67 (.681") ⚠️ |
| G max (entries 01 to 03) | 17.83 (.702") | 17.83 (.702") | 20.37 (.802") |
| Reference length behind the coupling | 11.43 (.450") | 12.70 (.50") | 21.84 (.860") |
| Compression nut thickness | 5.6 (.22") | 3.8 (.15") | 14.7 (.58") |
| Saddle clamp dimension columns | H · J · K | H · J · K · L | H · J · K |
Values are in millimeters with inches in parentheses. Anything not listed here is the same across all three types — the A thread by size code, D · F · H · J of the cable entry, and the sealing diameter ranges.
EMI has one extra saddle clamp dimension (K), so what is K on the environmental version becomes L on EMI. The same letter is a different dimension on a different type, so take care.
Tolerances on H and K are ±0.38 mm for environmental and EMI, and ±0.25 mm for environmental EMI.
For environmental EMI the E max inch and millimeter figures do not agree in the catalog (.681" = 17.30 mm, but 14.67 is printed). The source alone does not settle which is the typo, so it is reproduced as printed — if this dimension matters to you we will confirm it per P/N.
The drawing and the two tables above are for the environmental backshell (2M370M…). EMI (2M380M…) and environmental EMI (2M390M…) are mostly identical, and only the cells that differ are collected in the third table — the form is the same too, apart from the EMI ring. Choose the cable entry code from the sealing diameter range: the cable outer diameter has to fall within the range for the seal to work.
Q&A
Frequently Asked Questions
Can 2M be used in place of D38999?
If the drawing calls out MIL-DTL-38999, it cannot be substituted. 2M is a separate Amphenol micro-miniature connector family, and for 2M805 the manufacturer says only that it "meets D38999 requirements at half the size and weight" — it does not say MIL-DTL-38999 qualified. For a new design with no specification imposed where size and weight are the constraint, however, it is worth considering. Tell us which situation you are in and we will work through it with you.
Should I choose 2M801 or 2M805?
The manufacturer places 2M801 in the legacy category and recommends 2M805 as its successor. 2M805 uses a triple-start thread, so it takes fewer turns to mate, and an EMI band improves shell-to-shell conductivity and shielding. Where compatibility and interoperability with existing equipment or cabling has to be preserved, though, 2M801 is the right one. Tell us whether this is a new design or a match to existing assets and we will guide you.
Is 2M801 being discontinued?
It is classified as a legacy family, but there is no discontinuation notice. If you are planning long-term procurement, it is safer to have us confirm current availability and lead time before you order. Send us the P/N and we will check.
Do you supply shrink boots and backshells as well?
Yes. There is a separate accessory line covering every 2M connector family — backshells (environmental, EMI, environmental EMI), shrink boots, protective caps, strain relief, micro band adapters and more, all ordered as separate items from the connector. ADMTEC keeps 2M shrink boots in Korean stock.
Can it be used in high-vibration environments?
There is a separate 2M805 version built for high-vibration conditions. Tell us the vibration conditions of your application and we will review it against that version and advise.
Can I get a C of C with the order?
Yes. We issue one for every order — what it covers and the original certificate are on the Authorized Distributor certification page.
Specification sources11 documents · tap to expand
Family line-up and specification comparison: Amphenol Aerospace Micro38999 catalog (2024-02 edition) p.3 · Size and weight comparison: Amphenol Aerospace Micro38999 catalog (2024-02 edition) p.4 (2M805) · p.5 (2M801) · Insert arrangements: Amphenol Aerospace Micro38999 catalog p.6 Insert Arrangements — arrangement detail and footnotes on p.7 to p.9 · Part number code system (four families): Amphenol Aerospace Micro38999 catalog Ordering Guide — 2M805 p.29 · 2M804 p.42 · 2M803 p.60 · 2M801 p.70 · Performance and materials specifications: Amphenol Aerospace Micro38999 catalog p.21 Materials and Finishes · p.22 to p.27 Complete Product Specifications · separate 2M Series Performance Specifications document (7 pages) · Hermetic: Amphenol Aerospace Micro38999 catalog p.83 overview · ordering guides p.84 (2M805-006) · p.88 (2M804-006) · p.91 (2M803-006) · p.93 (2M801-012) · Backshell dimensions (environmental): Amphenol Aerospace Micro38999 catalog p.112 (environmental) · p.114 (EMI) · p.116 (environmental EMI) — the drawing was rendered from vector at scale 5 and cropped · Contacts, tooling and torque: Amphenol Aerospace Micro38999 catalog p.100 (crimp contacts · tooling · torque) · p.103 (grommet sealing plugs) · Accessory part numbers: Amphenol Aerospace Micro38999 catalog accessories section p.99 to p.124 (backshell ordering information p.111 · p.113 · p.115 · flange gaskets p.122 · p.123 · O-rings p.124) · Shrink boots: 2M809S060-1G Data Sheet (2M Series Backshells and Accessories) · Micro38999 catalog p.119 to p.120 · Manufacturing: Amphenol Aerospace. We confirm the latest revision and the exact applicable specification with you when we quote.