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What People Forget

A connector is never just the connector. The same items get left off BOMs, drawings, and orders over and over — and each one turns a good selection into a build that stalls, leaks, or fails in the field. Scan this list before you call an interface "done."

Everything here is covered in more depth elsewhere in the guide; this page just puts the usual suspects in one place.

Parts that fall off the BOM​

  • Mating connector — order both halves. A receptacle without its plug is half an interface, and procurement will buy exactly what the BOM says. (See Red Flags.)
  • Contacts — some part numbers ship without contacts ("less-contact" versions). Verify whether contacts are included or ordered separately, and match the correct crimp contacts. (See MIL-DTL-38999 §7.1.)
  • Backshell — strain relief, shield termination, sealing, and cable exit angle live here. It is not optional. (See Connector Anatomy.)
  • Cap / dust cover — an unmated connector needs protection from dirt, water, and pin damage. Put the cap P/N on the BOM. (See Connector Anatomy.)
  • Sealing plugs — every unused cavity in a sealed connector is an open hole. Plug it. (See Wire seals §5.5.)

Tooling and process​

  • Crimp tooling — the right calibrated crimp tool and positioner/die for the exact contact. A crimp that passes visual with the wrong tool still fails in vibration. (See Selection Workflow §4.)
  • Insertion / extraction tools — removable contacts need the matching insert/extract tool for build and repair. (See Practical Checklist.)
  • Torque procedure — coupling and jam-nut torque affect sealing and anti-vibration performance. Finger-tight is not a sealed, engaged mate. (See M12 §8.3.)
  • Acceptance standard — name the workmanship/acceptance criteria the harness will be built and inspected to (commonly IPC/WHMA-A-620, or the program/customer equivalent), alongside the manufacturer application spec for the exact contact system. (See Selection Workflow §4.)

Specs that decide whether it fits​

  • Cable OD / gland range — the cable jacket OD must fall inside the backshell gland/clamp range or the seal and strain relief do not work. (See Selection Workflow §4.)
  • Wire seal range — each contact cavity's wire seal is sized for a wire-OD range. Undersized wire leaks at that cavity even if everything else is perfect. (See Wire seals §5.5.)
  • Keying / polarization — assign a unique key position across similar connectors so cables can't be swapped or mis-mated. (See MIL-DTL-38999 §7.7.)

Documentation and supply​

  • Cable drawing — wire schedule, colors, gauges, shields, pairs, labels, and test requirements, formatted like a real drawing. (See Tools & Templates.)
  • ICD entry — the interface control definition procurement and manufacturing build from. (See Tools & Templates.)
  • Source-controlled pinout — a released, rev-controlled pinout, not tribal knowledge in someone's notebook. (See Red Flags.)
  • Lead time / second source — a perfect connector with a 40-week lead time and no second source is a schedule failure. Check availability and QPL/second-source options early. (See Selection Workflow §4.)
note

If you want a structured pass instead of a scan, the Connector Selection Checklist and Design Review Checklist fold every item above into a checkable sequence.