Amphenol Grommet Nut Backshell

ECONOMIC STRAIN RELIEF FOR CIRCULAR GROMMET SUPPORT

PEI-Genesis carries a wide array of backshell accessories for circular connectors. The Grommet Nut by Amphenol is an economical choice for grommet support and strain relief. Amphenol Back Nut provides a good grommet-holding force for the crimp connector when expensive and heavy backshells are unnecessary. Such holding force is essential to support the contacts and grommet in place when terminated with wire bundles. Not sure if your application requires a grommet nut or other accessory? Contact us today to discuss your application and allow us to guide you to the right decision.

TECH
SPECS
CREATE
PART NUMBER
DIMENSIONS

MATERIALS & FINISHES

AMPHENOL GROMMET NUT BACKSHELL MATERIALS & FINISHES

Aluminum Parts:

As per ASTM B 211, 221, 209, 85, 26

Steel Parts:

300 series, as per AMS-QQ-S-763/ASTM A 582

Elastomers:

Fluorosilicone, Silicone

Other Parts:

Suitable corrosion resistant material

AMPHENOL GROMMET NUT BACKSHELL TABLE-2 PLATING FINISHES

Amphenol Designation

MIL Designation

Finish

Guiding Specifications/Requirements

Anodize, Black*

To meet AS85049 requirements

Anodize, Hard*

AMS-A-8625, Type-III, Class -1

Nickel, Bright

AMS-QQ-290, Class-1, Grade-F

Electroless Nickel

AMS-C-26074, Class-4, Grade-B

Electroless Nickel

To meet AS85049 requirements

Cadmium, Bright

AMS-QQ-P-416, Type-I, Class-2

Cadmium, Olive Drab

AMS-QQ-P-416, Type-II, Class-3

Cadmium, Olive drab over Electroless Nickel

AMS-QQ-P-416, Type-II, Class-3 (Cadium); AMS-C-26074, Class-4, Grade-B (Nickel)

Cadmium, Olive drab over Electroless Nickel

To meet AS85049 requirements

Zinc-Cobalt, Dark Olive drab

ASTM-BB40

Zinc-Cobalt, Black

ASTM-BB40

*Non conductive coatings

ASSEMBLY TORQUE VALUES

AMPHENOL GROMMET NUT BACKSHELL ASSEMBLY TORQUE VALUES

Connector Shell Size

Torque (Inch-Pounds)

8, 9

3, 10, 10SL, 11

7, 12, 12S, 13

14, 14S, 15

16, 16S, 17

18, 19, 27

20, 21, 37

22, 23

24, 25, 61

100

STYLE-2 CONFIGURATION

AMPHENOL GROMMET NUT BACKSHELL STYLE-2 CONFIGURATION

Some design consideration will require bigger diameter cable to be terminated in the smaller shell size connectors. Cable with heavy/thicker shielding, many wires for different branches/routing are some of the examples. Such cable termination will require a bigger adapter body with cable entry dimensions greater than the connector rear side dimensions. Amphenol also supports this kind of application. The coupling end of the adapter will be modified to Style-2 design as shown in the figure below in such cases. The overall length of the Style-2 design adapters would be increased by approx. 1 inch (25.mm) as shown. This alternative design is applicable for all the Backshell Families listed in this catalog.

M85049/31

AMPHENOL GROMMET NUT BACKSHELL M85049/31 MIL-DTL-26482 SERIES II, MIL-DTL-5015 MATRIC (MS345X),
MIL-DTL-83723 SERIES III STRAIGHT SELF-LOCK/NON SELF-LOCK CREATE PART NUMBER EXAMPLE: M85049/31S12W

M85049/

MIL SERIES

SLASH SHEET
31: Straight

COUPLING
S: Self-Lock
"-": Non Self-Lock

DASH NUMBER
See Table-A

FINISH
See Table-2

M85049/27

AMPHENOL GROMMET NUT BACKSHELL M85049/27 MIL-DTL-38999 SERIES II & I STRAIGHT SELF-LOCK/NON SELF-LOCK CREATE PART NUMBER EXAMPLE: M85049/27S12W

M85049/

MIL SERIES

SLASH SHEET
27: Straight

COUPLING
S: Self-Lock
"-": Non Self-Lock

DASH NUMBER
See Table-B

FINISH
See Table-2

M85049/14

AMPHENOL GROMMET NUT BACKSHELL M85049/14 MIL-DTL-38999 SERIES III & SERIES IV STRAIGHT
SELF-LOCK/NON SELF-LOCK CREATE PART NUMBER EXAMPLE: M85049/14S15W

M85049/

MIL SERIES

SLASH SHEET
14: Straight

COUPLING
S: Self-Lock
"-": Non Self-Lock

SHELL SIZE
See Table-C

FINISH
See Table-2

M85049/31

AMPHENOL GROMMET NUT BACKSHELL M85049/31 MIL-DTL-26482 SERIES II, MIL-DTL-5015 MATRIX (MS345X),
MIL-DTL-83723 SERIES III STRAIGHT SELF-LOCK/NON SELF-LOCK DIMENSIONS

Table - A

Mil Part Number Designator
Dash No.

Connector
Shell Size

A Dia.
Max.

B Dia.
Max.

C
Max.

D
Max.

E Dia.
Max.

0.62 (15.67)

0.89 (22.48)

0.54 (13.72)

0.71 (18.03)

0.27 (6.86)

0.73 (18.64)

1.01 (25.65)

0.54 (13.72)

0.71 (18.03)

0.38 (9.53)

07 / 12

0.86 (21.79)

1.14 (28.83)

0.54 (13.72)

0.71 (18.03)

0.51 (12.98)

12 / 14

0.98 (24.99)

1.26 (32.00)

0.54 (13.72)

0.71 (18.03)

0.59 (14.86)

19 / 16

1.11 (28.24)

1.39 (35.18)

0.54 (13.72)

0.71 (18.03)

27 / 18

1.22 (30.94)

1.51 (38.35)

0.54 (13.72)

0.71 (18.03)

0.79 (20.04)

37 / 20

1.35 (34.16)

1.64 (41.53)

0.54 (13.72)

0.71 (18.03)

0.91 (23.22)

1.47 (37.29)

1.76 (44.70)

0.54 (13.72)

0.71 (18.03)

1.04 (26.39)

1.59 (40.46)

1.89 (47.88)

0.54 (13.72)

0.71 (18.03)

1.15 (29.31)

1.97 (50.01)

2.14 (54.23)

0.70 (17.83)

0.89 (22.61)

1.39 (35.28)

2.22 (56.36)

2.40 (60.83)

0.70 (17.83)

0.89 (22.61)

1.64 (41.53)

2.47 (62.71)

2.64 (66.93)

0.70 (17.83)

0.89 (22.61)

1.85 (46.99)

2.72 (69.06)

2.89 (73.28)

0.70 (17.83)

0.89 (22.61)

2.07 (52.45)

2.97 (75.41)

3.14 (79.63)

0.70 (17.83)

0.89 (22.61)

2.32 (58.93)

3.22 (81.76)

3.39 (85.98)

0.70 (17.83)

0.89 (22.61)

2.57 (65.28)

All dimensions for reference only.
All dimensions in inches (millimeters in parentheses)

M85049/27

AMPHENOL GROMMET NUT BACKSHELL MIL-DTL-38999 SERIES II & I STRAIGHT SELF-LOCK/NON SELF-LOCK DIMENSIONS

Table - B

Mil Part Number Designator
Dash No.

Connector
Shell Size
Series II / I

A Dia.
Max.

B Dia.
Max.

C
Max.

D
Max.

E Dia.
Max.

8 / 9

0.75 (19.05)

0.86 (21.82)

0.54 (13.72)

0.59 (14.99)

0.27 (6.86)

10 / 11

0.85 (21.59)

0.98 (24.99)

0.54 (13.72)

0.59 (14.99)

0.41 (10.41)

12 / 13

1.00 (25.40)

1.16 (29.36)

0.54 (13.72)

0.59 (14.99)

0.53 (13.46)

14 / 15

1.10 (27.94)

1.28 (32.54)

0.54 (13.72)

0.59 (14.99)

0.65 (16.51)

16 / 17

1.25 (31.75)

1.41 (35.71)

0.54 (13.72)

0.59 (14.99)

0.78 (19.81)

18 / 19

1.40 (35.56)

1.52 (38.51)

0.54 (13.72)

0.59 (14.99)

0.88 (22.34)

20 / 21

1.50 (38.10)

1.64 (41.68)

0.54 (13.72)

0.59 (14.99)

1.01 (25.65)

22 / 23

1.65 (41.91)

1.77 (44.86)

0.54 (13.72)

0.59 (14.99)

1.13 (28.70)

24 / 25

1.75 (44.45)

1.89 (48.03)

0.54 (13.72)

0.59 (14.99)

1.26 (32.00)

All dimensions for reference only.
All dimensions in inches (millimeters in parentheses)

M85049/14

AMPHENOL GROMMET NUT BACKSHELL M85049/14 MIL-DTL-38999 SERIES III & IV STRAIGHT SELF-LOCK/NON SELF-LOCK DIMENSIONS

Table - C

MIL Part Number Designator

Connector Shell Size

Connector Shell Size
/ Code (Ref.)

A Dia. Max.

B Dia. Min.

09 / A

0.86 (21.79)

0.26 (6.71)

11 / B

0.98 (24.99)

0.39 (9.91)

13 / C

1.16 (29.39)

0.50 (12.80)

15 / D

1.28 (32.49)

0.63 (16.00)

17 / E

1.41 (35.71)

0.76 (19.20)

19 / F

1.52 (38.51)

0.84 (21.41)

21 / G

1.64 (41.71)

0.97 (24.64)

23 / H

1.77 (44.91)

1.09 (27.71)

25 / J

1.87 (47.98)

1.22 (30.91)

All dimensions for reference only.
All dimensions in inches (millimeters in parentheses)