Locking Strain Relief Backshell — Shell 10, Electroless Nickel, MIL-DTL-38999

Specifications

Part Number Decode

In M85049/52S10N the S is the significant character: it marks the self-locking build, which contains a locking mechanism that resists the backshell rotating off the connector accessory thread under vibration. A plain /52 without the S offers strain relief but not the anti-rotation feature. The N finish is Electroless Nickel; the shell size is 10.

A QPL accessory specification — any manufacturer's M85049/52S10N is interchangeable with any other of the same shell size and finish.

Cross-Brand Compatibility

Locking strain relief is specified on engine-adjacent, rotorcraft and tracked-vehicle harnesses where vibration is continuous rather than transient. The failure mode it prevents is slow: the backshell backs off over hundreds of operating hours, the shield termination degrades, and the fault presents later as an intermittent shield or ground problem. Airoadcon supplies the locking and non-locking variants across the shell matrix.