AN3 at a glance
| Dimension | Value |
|---|---|
| Thread (T) | 10-32 UNF-3A |
| Shank diameter A, min – max | .186 – .189 in |
| Across flats B, min – max | .365 – .377 in |
| Head height D, min – max | .109 – .141 in |
| Cotter pin hole drill J (shank) | .070 in, +.010 −.000 |
| Safety wire hole drill K (head) | .046 in, +.010 −.000 |
| Dash numbers listed here | 3 to 45 |
From the dimension table of AN3 thru AN20 Rev. 12. Letters as on the standard's drawing.
Drawing
Grip and length by dash number
Find the grip that matches the stack of parts (see the bolt grip calculator), then read the part number off the row. Each row has its own link: /parts/an-bolts/an3/#AN3-16.
| Part no. | Dash | Grip, in ±1/64 | Length, in +1/32 −1/64 |
|---|---|---|---|
| AN3-3 | 3 | 1/16 | 15/32 |
| AN3-4 | 4 | 1/8 | 17/32 |
| AN3-5 | 5 | 1/4 | 21/32 |
| AN3-6 | 6 | 3/8 | 25/32 |
| AN3-7 | 7 | 1/2 | 29/32 |
| AN3-10 | 10 | 5/8 | 1-1/32 |
| AN3-11 | 11 | 3/4 | 1-5/32 |
| AN3-12 | 12 | 7/8 | 1-9/32 |
| AN3-13 | 13 | 1 | 1-13/32 |
| AN3-14 | 14 | 1-1/8 | 1-17/32 |
| AN3-15 | 15 | 1-1/4 | 1-21/32 |
| AN3-16 | 16 | 1-3/8 | 1-25/32 |
| AN3-17 | 17 | 1-1/2 | 1-29/32 |
| AN3-20 | 20 | 1-5/8 | 2-1/32 |
| AN3-21 | 21 | 1-3/4 | 2-5/32 |
| AN3-22 | 22 | 1-7/8 | 2-9/32 |
| AN3-23 | 23 | 2 | 2-13/32 |
| AN3-24 | 24 | 2-1/8 | 2-17/32 |
| AN3-25 | 25 | 2-1/4 | 2-21/32 |
| AN3-26 | 26 | 2-3/8 | 2-25/32 |
| AN3-27 | 27 | 2-1/2 | 2-29/32 |
| AN3-30 | 30 | 2-5/8 | 3-1/32 |
| AN3-31 | 31 | 2-3/4 | 3-5/32 |
| AN3-32 | 32 | 2-7/8 | 3-9/32 |
| AN3-33 | 33 | 3 | 3-13/32 |
| AN3-34 | 34 | 3-1/8 | 3-17/32 |
| AN3-35 | 35 | 3-1/4 | 3-21/32 |
| AN3-36 | 36 | 3-3/8 | 3-25/32 |
| AN3-37 | 37 | 3-1/2 | 3-29/32 |
| AN3-40 | 40 | 3-5/8 | 4-1/32 |
| AN3-41 | 41 | 3-3/4 | 4-5/32 |
| AN3-42 | 42 | 3-7/8 | 4-9/32 |
| AN3-43 | 43 | 4 | 4-13/32 |
| AN3-44 | 44 | 4-1/8 | 4-17/32 |
| AN3-45 | 45 | 4-1/4 | 4-21/32 |
Grip and length as tabulated on sheet 2 of AN3 thru AN20 Rev. 12. Every row has length − grip = 13/32 in on this standard: that is the threaded end, worked out here, not a figure the standard prints. The standard goes on to longer dash numbers; this sheet lists up to AN3-45.
How to read the part number
| Part | Meaning |
|---|---|
| AN4 | Standard and nominal diameter: AN3 = 3/16 in, then one sixteenth per step (AN4 = 1/4 in, AN8 = 1/2 in). |
| C before the dash | Corrosion-resistant steel. Nothing here = non-corrosion-resistant steel. |
| DD before the dash | Aluminum alloy. |
| H before the dash | Drilled head (for safety wire). |
| -12 | Dash number: sets grip and length, read off the table. First digit whole inches, second digit eighths. |
| A after the dash | Undrilled shank. No A = shank drilled for a cotter pin. |
Codes and examples from the notes on sheet 1 of AN3 thru AN20 Rev. 12.
Examples from the standard
| Part no. | Reads as |
|---|---|
| AN6-10 | 3/8 in steel bolt, 1-5/64 in long, 7/16 in grip, shank drilled |
| AN6C10 | Same, corrosion-resistant steel |
| AN6DD10A | Same, aluminum alloy, undrilled |
| AN6H10A | Same, steel, head drilled only |
Limits — when NOT to use this
- The aircraft's own data comes first. Where the maintenance manual or IPC names a bolt, use that part number. This sheet tells you what the number means, not whether it fits your aircraft.
- Superseded standard. Cancelled by Notice 1 (Dec 1999) and superseded by NASM3 thru NASM20; the notice states the part numbers are identical. Check the current NASM revision before buying to a drawing.
- Material and strength come from the procurement specification the standard points to, not from this sheet. Torque values are not on this page.
- Measure before ordering when replacing original hardware: AC 43.13-1B par. 7-37 notes that specifications have changed over the years.
Sources
- AN3 thru AN20 Rev. 12, 14 Jan 1991 — Bolt — Machine, Aircraft — dimension table and notes (sheet 1), grip and length table (sheet 2). Public domain, distribution unlimited.
- FAA AC 43.13-1B, par. 7-37 — grip length and the washer limit.
Educational reference only. not approved data. Always consult the applicable SRM, AMM, or AC 43.13-1B and your certifying authority.