AN Hardware Decoder

Enter an AN part number to decode its meaning — bolt size, nut type, washer spec, or cotter pin dimensions.

Part Number

Case-insensitive. Try: AN4-10A, AN310-428, AN380-2-2, AN960-416

Common AN Hardware Reference

Quick reference for AN series part number prefixes

Code	Type	Notes
AN3–AN20	Hex Head Bolt	Diameter code = bolt dash size. Length in 1/8" increments.
AN310	Castle Nut	For use with cotter pin (AN380). Castellated hex nut.
AN315	Plain Hex Nut (RH)	Standard right-hand thread plain nut.
AN316	Plain Hex Nut (LH)	Left-hand thread. Used on rotating shafts.
AN320	Wing Nut	Hand-tightening only. Non-structural.
AN362	Self-Locking Nut (Thin)	Thin all-metal prevailing torque nut.
AN364	Self-Locking Nut	Fiber insert. Max 250°F. Do not reuse.
AN365	Self-Locking Nut	Standard all-metal. Preferred for elevated temps.
AN366	Self-Locking Nut (Light)	Lightweight variant. Verify load capacity.
AN380	Cotter Pin	Diameter in 1/32", length in 1/4". Always use new.
AN960	Flat Washer	Standard flat washer for bolt/nut applications.
AN970	Large Area Washer	For soft materials. Greater load distribution.

Important Disclaimer

This tool is provided for educational and reference purposes only. Always verify all calculations against FAA-approved maintenance manuals, aircraft documentation, and applicable regulations. Never use web-based tools as the sole basis for airworthiness decisions.