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Source Notes — Connector Engineering Field Guide

This file tracks claims that should be verified against a primary source (a current manufacturer datasheet, the applicable standard, or a QPL listing) before public/open-source release or before any of these values is used in released hardware.

Every item below also appears as a <!-- TODO: source/verify --> comment at the relevant location in the guide. Numbers in the guide are presented as examples requiring verification, not as universal ratings.

Source discipline (publication rules)​

  • Do not reproduce paid standards tables (the body text or tables of MIL-DTL or IEC documents) in this guide or derivatives. Reference and link instead.
  • Do not copy proprietary catalog tables verbatim. Verify against public manufacturer datasheets and summarize in your own words.
  • Manufacturer, standard, trademark, and connector-family names remain property of their owners; used here for identification and education only.

Claims to verify​

MIL-DTL-38999​

  • Part-number decoder example (D38999/26WE26PN) — confirm each field (/26 straight plug, W finish class, E → shell size 17, 26 arrangement, P pin, N normal) against a specific manufacturer's published decoder (e.g. Amphenol Aerospace). Note explicitly that schemas differ between Amphenol / Glenair / Souriau / ITT Cannon / TE / Eaton.
  • Series I/II/III/IV coupling descriptions (bayonet / low-profile bayonet / Tri-Start triple-start thread / breech-lock) — confirm against the MIL-DTL-38999 spec and manufacturer literature.
  • Shell sizes, approximate OD, and "typical contact range" in Section 7.3 — approximate OD figures and contact-range orientation values need a manufacturer source; they are labeled as orientation aids, not selection rules.
  • Contact-size / current example table (Sections 7.5 and A2: 22D≈3 A, 20≈5 A, 16≈10 A, 12≈17 A) — these are example test currents from a manufacturer contact-performance spec, not continuous ratings. Confirm against the specific AS39029 contact datasheet for the contact P/N actually used.
  • Keying positions (N, A, B, C, D, E) — confirm against the manufacturer catalog for the specific connector.
  • High-current guidance (size 12 only where derating supports the load; size 8/larger or HCP/RADSOK for higher current) — confirm contact current curves and the no-paralleling-without-review caution against the manufacturer derating data.

MIL-DTL-24308 (D-sub)​

  • "Standard D-sub is non-environmental" statement — confirm against MIL-DTL-24308 scope. Note that ruggedized/environmental variants exist.

MIL-DTL-83513 (Micro-D)​

  • Pitch and contact-arrangement statements — confirm fine-pitch and arrangement ranges against the spec / manufacturer catalog before stating any specific numbers. Current guide avoids exact contact counts pending verification.

M12 (IEC 61076-2-x)​

  • Standards mapping — confirm IEC 61076-2-101 (A/B/D), 61076-2-109 (X-coded), 61076-2-111 (S/T/K/L power) reference numbers and current editions. Do not reproduce IEC tables.
  • A-coded "~4 A class" — confirm the typical A-coded current class against catalog/standard scope; emphasize it is connector/cable/temperature dependent.
  • D-coded vs X-coded Ethernet guidance — confirm D-coded = 10/100BASE-TX, X-coded = GbE/10G-class against standards/manufacturer literature. D-coded is not obsolete; X-coded is not a blanket default.
  • Common coupling torque (~0.4–0.6 N·m) — labeled as an example; confirm against the specific connector's datasheet.

JST​

  • Family pitch/current statements (XH 2.5 mm, PH 2.0 mm, GH 1.25 mm, SH 1.0 mm, VH 3.96 mm, EH/ZH; VH "higher-current in some configurations") — confirm against JST datasheets for each series. "JST" alone is not a specification.

Consumer I/O​

  • USB-C mating-cycle expectation — if an exact cycle count (e.g. 10,000) is ever added, attach a source. Current guide states "high mating-cycle expectations" without a number and warns cycle life ≠ ruggedness.
  • HDMI — no cycle rating quoted; keep it that way unless sourced.

IP ratings (IEC 60529 / ISO 20653)​

  • IP definitions table (IP54/65/67/68/69K) — confirm wording against IEC 60529; do not reproduce the standard's table.
  • IP69K → ISO 20653 (DIN 40050-9 lineage) distinction — confirm the "K" suffix origin and the IPx9 relationship; keep IP69K out of "IEC 60529" attribution.
  • IP67 ≈ 1 m / 30 min — labeled "per standard test"; confirm exact test condition wording against IEC 60529.

General​

  • Any remaining current, voltage, mating-cycle, temperature, insulation-resistance, contact-resistance, wire-gauge, pitch, or contact-count number should be source-backed, labeled as an example, or replaced with cautious wording before release.

Intentional engineering heuristics (not hard facts)​

These are deliberately presented as design heuristics / judgment, not as standards-backed rules:

  • Spare-position guidance (Section 4) — "add spares where feasible and justified" replaces any fixed percentage. Explicitly a heuristic; shell size, weight, cost, sealing plugs, and program requirements may override.
  • Conservative current derating margin (Sections 4 and 10) — "use a conservative margin and the manufacturer derating curve" rather than a fixed percentage.
  • Mating-cycle service-life margin (Sections 3/6) — "service life with margin below the rated cycles" rather than a fixed multiplier.
  • Locking-mechanism preference (Section 4) — "threaded/self-locking is often preferred for severe vibration" is judgment, not an absolute; bayonet is not categorically rejected.
  • Series III as the often-default 38999 choice (Section 7.2) — a common-practice heuristic, conditioned on size/mating-speed/legacy/customer/program requirements.
  • Bench-to-product transition rule of thumb (Section 12.3) — a judgment checklist, not a spec.