An accessory must match the connector interface and the installation. Start with the connector's specification, series, shell size, rear accessory thread, finish, and the cable or harness requirements. Then verify the accessory's detail sheet, dimensions, materials, and approved configuration.
M85049 covers a family of electrical connector accessories. The exact part-number pattern depends on the accessory type and its detail sheet; there is no single suffix format that applies to every accessory. For example, this /16 strain-relief pattern is M85049/16S11W:
In this example, /16 identifies the accessory sheet, S selects the self-locking configuration, 11 is the shell size, and W is the finish code. Other sheets can use different fields, separators, and order. Always decode a part number against its own current detail sheet.
Backshell and connector-side accessories
Backshells attach to the rear of a connector and provide a mechanical or electrical interface for cable routing, strain control, environmental protection, or shield termination. The correct style depends on the connector's accessory thread, shell size, cable bundle, routing direction, sealing requirements, and shielding design.
Strain-relief backshells — /16, /38, /39, /91, /92
Use strain relief when the cable bundle needs support at the connector exit to reduce pull and bending loads transferred into the connector and terminations. Choose among the represented sheets based on cable direction, locking configuration, and specified material:
/16— 90-degree self-locking strain relief. Choose it when the cable needs to turn 90 degrees at the connector and the installation calls for its self-locking coupling. Its strain-relief arm can be secured with the tie, twine, or lacing methods named on the sheet; a grounding-lug configuration is also represented. Check the entry maximum and contact-size exclusions./38— straight strain relief. Choose it for a straight cable exit when either a self-locking or non-self-locking configuration is required. The sheet provides a wire-bundle accommodation range and multiple finishes; its non-self-locking PIN uses a dash in the configuration position./39— 90-degree strain relief. Choose it for a right-angle cable exit when the sheet's self-locking or non-self-locking configuration is appropriate. Its non-self-locking configuration position is left blank, unlike/38; follow the exact sheet syntax./91— straight composite strain relief, self-locking. Choose it when the design specifies this composite, straight-exit style. Its cable-entry diameter is given with the saddle bars closed against the clamp ears, so compare the bundle against that defined measurement condition./92— 90-degree composite strain relief, self-locking. Choose it when the same composite style is required but the cable must exit at 90 degrees. Apply the sheet's cable-entry measurement condition and check compatibility for the exact connector.
The builder's data flags /16, /38, /39, /91, and /92 as unsuitable for connectors using size 8, 4, or 0 contacts. Check that constraint along with shell-size-specific cable entry before selecting one.
Backshells with cable clamps — /18, /19, /21
Use one of these when the cable needs a backshell-mounted clamp and a straight exit. Choose the sheet according to the environmental and shielding features required by the design:
/18— environmental, RFI/EMI backshell. Choose it when the installation calls for the sheet's environmental style together with its RFI/EMI provision. Select a clamp size for the measured cable diameter and a length that fits the assembly envelope./19— non-environmental, RFI/EMI backshell. Choose it when the RFI/EMI style is needed but the environmental version is not required by the design. Its cable-clamp ranges differ from/18, so select from/19's own sizing table./21— non-environmental backshell without the RFI/EMI designation. Choose it for a basic straight cable-clamp backshell when the other two sheets' environmental or RFI/EMI features are not called for. Check the finish and clamp range in its own sheet.
All three provide length choices in the current dataset. Compare the selected length, clamp range, and connector/cable clearances against the actual installation rather than treating the category labels as a complete environmental or EMC qualification.
Shield-termination backshells — /20, /78, /79, /85, /86, /87, /88, /89, /90
Use these styles when the cable shield must terminate at the connector-side backshell as part of the design's shielding path. The useful choice depends on the shield termination method, sealing requirement, and cable direction:
/20— straight RFI/EMI backshell with shield crimp ring. Choose it when the specified termination uses a crimp ring rather than the cone or band method. The sheet identifies the ring and crimp tooling; verify the ring, tool, and shield preparation together./78— 45-degree environmental shield-termination backshell. Choose it when the shield is terminated with the sheet's single-shield, single-cone arrangement, an environmental backshell is required, and a 45-degree exit suits the cable route./79— 90-degree environmental shield-termination backshell. Choose it for the same single-shield, single-cone termination when a 90-degree exit is needed. The source sheet says it does not fit MIL-C-38999 Series IV jam-nut receptacles; the builder excludes that combination. Check the exact interface before use./85— straight-exit band termination for Series I/II. Choose this family when the cable can run directly behind the connector and the design calls for a shield band plus a heat-shrink boot interface. It is specified for MIL-DTL-38999 Series I/II applications in Category 3B; verify the connector interface and the selected band and boot./86— angled band termination for Series I/II. Its 45-degree cable exit can help route the harness around nearby structure when a straight backshell would take too much axial room. Check the cable's bend radius and installation clearance./87— right-angle band termination for Series I/II. Its 90-degree cable exit can suit compact layouts that require the harness to turn at the connector. Confirm cable-entry limits, bend radius, and clearance; the backshell angle does not define the cable's allowable bend radius./88— straight-exit band termination for Series III/IV. Select it when the cable runs directly back and the shield is attached with a separate band. Size the cable entry and band to the specific backshell and cable construction./89— 45-degree band termination for Series III/IV. Use this exit direction when the harness needs to turn away from the connector while retaining the band's shield attachment method./90— 90-degree band termination for Series III/IV. Choose it when the cable must turn at a right angle near the connector; check bend radius and surrounding clearance before committing to the layout.
For /88–/90, pair the backshell with a compatible /128 shield band and its installation tool. Do not interchange the crimp-ring, cone, and band approaches without checking the applicable detail sheets and the system shielding design.
The /85–/87 family is for MIL-DTL-38999 Series I/II; /88–/90 is for Series III/IV. Within each family, the three sheet numbers map to straight, 45-degree, and 90-degree cable exits. Similar termination methods do not make the series interfaces interchangeable. The /85 specification also identifies Category 3B and a heat-shrink boot interface. Check the applicable current detail sheet and connector compatibility before selection. SAE AS85049/85.
Shrink-boot adapter — /69
Choose the /69 adapter when the design calls for a heat-shrink boot and needs the corresponding connector-side seat/interface. Confirm the adapter's actual diameter and groove, the boot's recovered and supplied dimensions, and the compatibility statements on both detail sheets. The /69 sheet historically names M85049/68 boots; that older boot specification has been canceled and superseded. Do not assume every boot fits every adapter solely because the family number is M85049.
Cable protection and harness accessories
Heat-shrink boots — /140, /141
Use a heat-shrink boot around a compatible backshell and cable exit when the design needs a protected transition from the connector to the wire bundle. /140 is a straight boot family; /141 is a 90-degree family. Style, size, material, adhesive, drain, and port options affect fit and use. Match the adapter-end size and the cable-end diameter to the actual assembly and installation requirements.
The site's boot dimensions and ordering options come from secondary sources, because the current SAE sheets were not available when the data was entered. Verify the exact part against the current SAE-AS85049 sheet and the product's own documentation.
Heat-shrink transitions — /142
Use a transition to protect a cable branch or breakout, such as a tee, wye, or one-to-three transition. These transitions join and protect cables; they are not selected by connector shell size. Choose the style and size based on the cable diameters, branch geometry, material, adhesive, and installation space.
Shield bands — /128
Use a shield band to clamp a cable shield onto a compatible shield-band backshell, including represented /88–/90 styles. The band and installation tool must match the backshell surface and the cable/shield construction. Band sizes and tooling information on the site come from secondary sources, not a direct review of the SAE sheet; verify the exact combination against the current SAE sheet and the product's own documentation.
Contact-cavity accessories
Dummy contacts — /80
Use a dummy contact in an unwired contact cavity where the applicable connector instructions call for a dummy in place of an unused contact and sealing plug. The represented data covers size 12 and size 8 variants. Confirm the connector family, cavity size, sealing requirement, and insertion/removal tool from the sheet before assembly.
Seal plugs — /81
Use a seal plug to close an unused size 10 contact cavity where the connector/contact system calls for one. The represented /81 option is size 10. The detail sheet's tool table lists tools for sizes 12 and 8 rather than size 10, so verify the correct installation tool and procedure with the current controlling documentation.
Protective covers and dust caps
Protective covers and dust caps shield an unmated connector interface from handling damage and contamination during storage, transport, or maintenance. The Series III/IV M85049 dataset lists the plastic /138 dust-cap category but does not build its part numbers. The MIL-DTL-26482 Series 2 accessory data separately includes MS3180 plug covers and MS3181 receptacle covers. Check whether a cover is qualified for the exact connector interface; covers are not substitutes for mating connectors or cavity seal plugs.
Choosing the right accessory
- Identify the connector's exact standard, series, shell style, shell size, and rear accessory interface.
- Define the actual need: strain support, cable clamping, environmental protection, shield termination, boot transition, cavity sealing, or protection while unmated.
- Check cable bundle diameter, exit angle, material/finish, environmental conditions, shielding method, and installation space.
- Build or decode the accessory part number using the accessory's own sheet format.
- Verify dimensions, compatibility, installation tooling, current revision, and supplier availability before release or purchase.
The EMech WorkBench builders narrow the options for the connector series and accessory data they currently support: choose the connector first, and the accessory choices follow from it. A builder may disable a choice when its data identifies an incompatibility, and it may omit options that are not in its data. An option missing from the tool may be a coverage gap, not a statement that the accessory is invalid or unavailable. An option that appears in the tool does not replace checking the current specification and product documentation.
Current data scope
For MIL-DTL-38999 Series III and IV, the builders offer a subset of M85049 accessories: strain reliefs, cable-clamp backshells, shield-termination backshells, a shrink-boot adapter, heat-shrink boots and transitions, shield bands, dummy contacts, and seal plugs. Several SAE-only sheets are listed without full part-number building, and some accessory families—including the /138 dust cap—are not selectable. The Series I and II builders have a single accessory sheet, /32, a 90-degree shield-termination backshell; the Series I/II band-termination sheets /85–/87 described above are not built in any builder. The MIL-DTL-26482 Series 2 builder has its own backshell and protective-cover data. The MIL-DTL-5015 and MIL-DTL-83723 Series III builders offer the M85049 backshells for their crimp connectors, plus protective covers and a seal plug. Use the specific connector builder's visible coverage notes.
Many older MIL-C-85049 sheets were canceled and superseded by SAE-AS85049. The site's data cites the source edition and warns where secondary sources were used. Confirm the current SAE sheet and supplier documentation for the exact part.
The site does not provide a complete M85049 catalog, a universal cross-series fit guarantee, or live supplier inventory, price, or lead time. An absent accessory result may reflect data coverage rather than nonexistence. Confirm the exact part and its availability with the supplier.