These hexagon head, unified thread aircraft bolts are made of high-strength 4037 or 8740 type alloy steel (type 8740 is most commonly used). The bolts are centreless ground and threaded after heat treatment, minimum tensile strength 125,000 PSI, cadmium plated per specification QQ-P-416A, Type II, Class 3. Available with shank drilled for cotter pin or undrilled for stiffnut application, and with head drilled or undrilled for locking wire.

The first digit of an AN bolt part number denotes the diameter of the bolt in sixteenths of an inch, for example all AN3 bolts are 3/16” diameter, AN7 is 7/16” diameter and so on. The dash number works by denoting the whole length (including the thread) in eighths of an inch in a way that only the American’s could have invented! The easiest way to explain this is by example:- AN3-14A denotes a bolt which is not 14 eighths of an inch long but 1 whole inch and four eighths, so AN3-35A is three whole inches and five eighths long. Thus, you cannot have an AN bolt such as AN5-48A as this would be four whole inches and eight eighths, which would in fact be an AN4-50A - five whole inches and no eighths! However please note that the actual measured length is slightly longer as per the tables.

A common mistake made when ordering is to omit the A from the end of part number. AN bolts were originally designed before widespread use of stiffnuts so all AN bolts were drilled in the thread and that is the standard. If you want an undrilled bolt you must add an A after the part number - it has been suggested that the A stands for “Absent”.

Also remember that if you want a castle or stiffnut to match your bolt the dash numbers will tie up with other American hardware, so for an AN3 bolt the castle nut is an AN310-3 and the stiffnut is an MS21044-N3.

AN3 (#10-32 or 3/16”-32)
Nominal Length	Grip Length	Drilled		Undrilled “A”
		Part No	Price	Part No	Price
15/32	1/16	AN3-3	£0.70	AN3-3A	£0.07
17/32	1/8	AN3-4	£0.36	AN3-4A	£0.07
21/32	1/4	AN3-5	£0.36	AN3-5A	£0.08
25/32	3/8	AN3-6	£0.44	AN3-6A	£0.08
29/32	1/2	AN3-7	£0.40	AN3-7A	£0.07
1-1/32	5/8	AN3-10	£0.44	AN3-10A	£0.11
1-5/32	3/4	AN3-11	£0.34	AN3-11A	£0.15
1-9/32	7/8	AN3-12	£0.32	AN3-12A	£0.14
1-13/32	1	AN3-13	£0.96	AN3-13A	£0.15
1-17/32	1-1/8	AN3-14	£0.36	AN3-14A	£0.14
1-21/32	1-1/4	AN3-15	£0.53	AN3-15A	£0.18
1-25/32	1-3/8	AN3-16	£0.67	AN3-16A	£0.17
1-29/32	1-1/2	AN3-17	£0.77	AN3-17A	£0.19
2-1/32	1-5/8	AN3-20	£0.77	AN3-20A	£0.29
2-5/32	1-3/4	AN3-21	£0.72	AN3-21A	£0.22
2-9/32	1-7/8	AN3-22	£0.72	AN3-22A	£0.22
2-13/32	2	AN3-23	£0.77	AN3-23A	£0.62
2-17/32	2-1/8	AN3-24	£0.77	AN3-24A	£0.41
2-21/32	2-1/4	AN3-25	£0.77	AN3-25A	£0.56
2-25/32	2-3/8	AN3-26	£0.87	AN3-26A	£0.53
2-29/32	2-1/2	AN3-27	£0.92	AN3-27A	£0.82
3-1/32	2-5/8	AN3-30	£1.23	AN3-30A	£0.80
3-5/32	2-3/4	AN3-31	£0.49	AN3-31A	£1.03
3-9/32	2-7/8	AN3-32	£1.13	AN3-32A	£0.46
3-13/32	3	AN3-33	£0.87	AN3-33A	£0.61
3-17/32	3-1/8	AN3-34	£0.72	AN3-34A	£0.54
3-21/32	3-1/4	AN3-35	£1.54	AN3-35A	£1.33
3-25/32	3-3/8	AN3-36	£1.70	AN3-36A	£1.44
3-29/32	3-1/2	AN3-37	£1.37	AN3-37A	£0.56
4-1/32	3-5/8	AN3-40	£2.05	AN3-40A	£1.03
4-5/32	3-3/4	AN3-41	£1.10	AN3-41A	£1.54
4-9/32	3-7/8	AN3-42	£0.92	AN3-42A	£0.72
4-13/32	4	AN3-43	POA	AN3-43A	£1.17
4-17/32	4-1/8	AN3-44	£2.05	AN3-44A	£2.05
4-21/32	4-1/4	AN3-45	£1.07	AN3-45A	£1.15
4-25/32	4-3/8	AN3-46	£1.44	AN3-46A	£0.96
4-29/32	4-1/2	AN3-47	£1.10	AN3-47A	£2.56
5-1/32	4-5/8	AN3-50	£10.02	AN3-50A	£7.64
5-5/32	4-3/4	AN3-51	£8.12	AN3-51A	£6.95
5-9/32	4-7/8	AN3-52	POA	AN3-52A	£6.77
5-13/32	5	AN3-53	POA	AN3-53A	POA
5-17/32	5-1/8	AN3-54	£7.58	AN3-54A	£8.32
5-21/32	5-1/4	AN3-55	POA	AN3-55A	£5.38
5-25/32	5-3/8	AN3-56	£8.71	AN3-56A	£8.32
5-29/32	5-1/2	AN3-57	POA	AN3-57A	£9.25
6-1/32	5-5/8	AN3-60	£8.43	AN3-60A	£9.25

AN4 (1/4”-28)
Nominal Length	Grip Length	Drilled		Undrilled “A”
		Part No	Price	Part No	Price
15/32	1/16	AN4-3	£0.29	AN4-3A	£0.17
17/32	1/16	AN4-4	£0.64	AN4-4A	£0.29
21/32	3/16	AN4-5	£0.63	AN4-5A	£0.13
25/32	5/16	AN4-6	£0.36	AN4-6A	£0.13
29/32	7/16	AN4-7	£0.84	AN4-7A	£0.16
1-1/32	9/16	AN4-10	£0.41	AN4-10A	£0.16
1-5/32	11/16	AN4-11	£0.58	AN4-11A	£0.20
1-9/32	13/16	AN4-12	£0.41	AN4-12A	£0.40
1-13/32	15/16	AN4-13	£0.69	AN4-13A	£0.23
1-17/32	1-1/16	AN4-14	£0.72	AN4-14A	£0.26
1-21/32	1-3/16	AN4-15	£0.62	AN4-15A	£0.23
1-25/32	1-5/16	AN4-16	£0.40	AN4-16A	£0.38
1-29/32	1-7/16	AN4-17	£0.87	AN4-17A	£0.30
2-1/32	1-9/16	AN4-20	£0.51	AN4-20A	£0.42
2-5/32	1-11/16	AN4-21	£1.00	AN4-21A	£0.22
2-9/32	1-13/16	AN4-22	£1.00	AN4-22A	£0.67
2-13/32	1-15/16	AN4-23	£0.79	AN4-23A	£0.72
2-17/32	2-1/16	AN4-24	£0.95	AN4-24A	£2.15
2-21/32	2-3/16	AN4-25	£1.31	AN4-25A	£1.03
2-25/32	2-5/16	AN4-26	£1.03	AN4-26A	£0.34
2-29/32	2-7/16	AN4-27	£1.00	AN4-27A	£0.50
3-1/32	2-9/16	AN4-30	£0.53	AN4-30A	£0.49
3-5/32	2-11/16	AN4-31	£1.16	AN4-31A	£0.50
3-9/32	2-13/16	AN4-32	£1.13	AN4-32A	£0.77
3-13/32	2-15/16	AN4-33	£1.42	AN4-33A	£0.67
3-17/32	3-1/16	AN4-34	£1.03	AN4-34A	£0.62
3-21/32	3-3/16	AN4-35	£1.58	AN4-35A	£1.57
3-25/32	3-5/16	AN4-36	£2.31	AN4-36A	£0.95
3-29/32	3-7/16	AN4-37	£2.66	AN4-37A	£2.25
4-1/32	3-9/16	AN4-40	£2.82	AN4-40A	£1.08
4-5/32	3-11/16	AN4-41	£1.54	AN4-41A	£0.76
4-9/32	3-13/16	AN4-42	£3.08	AN4-42A	£1.01
4-13/32	3-15/16	AN4-43	£3.08	AN4-43A	£1.54
4-17/32	4-1/32	AN4-44	£5.64	AN4-44A	£1.37
4-21/32	4-3/16	AN4-45	£4.15	AN4-45A	£1.06
4-25/32	4-5/16	AN4-46	£2.79	AN4-46A	£0.97
4-29/32	4-7/16	AN4-47	£1.41	AN4-47A	£1.17
5-1/32	4-9/16	AN4-50	£3.40	AN4-50A	£2.17
5-5/32	4-11/16	AN4-51	£6.11	AN4-51A	£3.68
5-9/32	4-13/16	AN4-52	£7.16	AN4-52A	£7.12
5-13/32	4-15/16	AN4-53	POA	AN4-53A	£7.89
5-17/32	5-1/16	AN4-54	POA	AN4-54A	£6.89
5-21/32	5-3/16	AN4-55	£7.27	AN4-55A	£6.93
5-25/32	5-5/16	AN4-56	£6.58	AN4-56A	£7.35
5-29/32	5-7/16	AN4-57	£6.96	AN4-57A	£7.35
6-1/32	5-9/16	AN4-60	£7.35	AN4-60A	£3.29

AN5 (5/16”-24)
Nominal Length	Grip Length	Drilled		Undrilled “A”
		Part No	Price	Part No	Price
19/32	1/16	AN5-4	£0.51	AN5-4A	£0.31
23/32	3/16	AN5-5	£0.72	AN5-5A	£0.36
27/32	5/16	AN5-6	£1.21	AN5-6A	£0.32
31/32	7/16	AN5-7	£1.05	AN5-7A	£0.25
1-3/32	9/16	AN5-10	£0.89	AN5-10A	£0.22
1-7/32	11/16	AN5-11	£0.56	AN5-11A	£0.53
1-11/32	13/16	AN5-12	£0.96	AN5-12A	£0.43
1-15/32	15/16	AN5-13	£0.70	AN5-13A	£0.48
1-19/32	1-1/16	AN5-14	£0.69	AN5-14A	£0.34
1-23/32	1-3/16	AN5-15	£0.55	AN5-15A	£0.69
1-27/32	1-5/16	AN5-16	£1.20	AN5-16A	£0.79
1-31/32	1-7/16	AN5-17	£0.92	AN5-17A	£0.27
2-3/32	1-9/16	AN5-20	£0.78	AN5-20A	£0.53
2-7/32	1-11/16	AN5-21	£1.05	AN5-21A	£0.76
2-11/32	1-13/16	AN5-22	£0.81	AN5-22A	£1.23
2-15/32	1-15/16	AN5-23	£0.61	AN5-23A	£0.55
2-19/32	2-1/16	AN5-24	£0.77	AN5-24A	£0.74
2-23/32	2-3/16	AN5-25	£0.77	AN5-25A	£1.03
2-27/32	2-5/16	AN5-26	£5.16	AN5-26A	£0.53
2-31/32	2-7/16	AN5-27	£1.05	AN5-27A	£1.44
3-3/32	2-9/16	AN5-30	£1.85	AN5-30A	£1.54
3-7/32	2-11/16	AN5-31	£1.48	AN5-31A	£1.17
3-11/32	2-13/16	AN5-32	£2.56	AN5-32A	£1.00
3-15/32	2-15/16	AN5-33	£3.94	AN5-33A	£0.59
3-19/32	3-1/16	AN5-34	£8.15	AN5-34A	£2.05
3-23/32	3-3/16	AN5-35	£2.24	AN5-35A	£1.06
3-27/32	3-5/16	AN5-36	£2.16	AN5-36A	£1.61
3-31/32	3-7/16	AN5-37	£1.74	AN5-37A	£2.05
4-3/32	3-9/16	AN5-40	£4.00	AN5-40A	£2.82
4-7/32	3-11/16	AN5-41	£1.84	AN5-41A	£2.79
4-11/32	3-13/16	AN5-42	POA	AN5-42A	£1.30
4-15/32	3-15/16	AN5-43	£1.70	AN5-43A	£2.56
4-19/32	4-1/32	AN5-44	POA	AN5-44A	£3.00
4-23/32	4-3/16	AN5-45	£1.52	AN5-45A	£4.10
4-27/32	4-5/16	AN5-46	£3.95	AN5-46A	£1.54
4-31/32	4-7/16	AN5-47	£1.86	AN5-47A	£1.62
5-3/32	4-9/16	AN5-50	£6.11	AN5-50A	£4.45
5-7/32	4-11/16	AN5-51	£7.54	AN5-51A	£6.42
5-11/32	4-13/16	AN5-52	£7.93	AN5-52A	£7.58
5-15/32	4-15/16	AN5-53	£7.35	AN5-53A	£7.35
5-19/32	5-1/16	AN5-54	£6.17	AN5-54A	£7.68
5-23/32	5-3/16	AN5-55	£6.38	AN5-55A	£7.20
5-27/32	5-5/16	AN5-56	£6.42	AN5-56A	£7.58
5-31/32	5-7/16	AN5-57	£9.48	AN5-57A	£12.96
6-3/32	5-9/16	AN5-60	£8.32	AN5-60A	£7.66

AN6 (3/8”-24)
Nominal Length	Grip Length	Drilled		Undrilled “A”
		Part No	Price	Part No	Price
19/32	1/16	AN6-4	£0.49	AN6-4A	POA
23/32	1/16	AN6-5	£0.67	AN6-5A	£0.53
27/32	3/16	AN6-6	£0.51	AN6-6A	£0.55
31/32	5/16	AN6-7	£0.63	AN6-7A	£0.68
1-3/32	7/16	AN6-10	£0.72	AN6-10A	£0.50
1-7/32	9/16	AN6-11	£1.54	AN6-11A	£0.37
1-11/32	11/16	AN6-12	£2.18	AN6-12A	£0.62
1-15/32	13/16	AN6-13	£1.03	AN6-13A	£0.65
1-19/32	15/16	AN6-14	£1.54	AN6-14A	£0.80
1-23/32	1-1/16	AN6-15	£0.67	AN6-15A	£0.56
1-27/32	1-3/16	AN6-16	£2.53	AN6-16A	£0.84
1-31/32	1-5/16	AN6-17	£2.24	AN6-17A	£0.70
2-3/32	1-7/16	AN6-20	£1.16	AN6-20A	£0.77
2-7/32	1-9/16	AN6-21	£1.39	AN6-21A	£1.53
2-11/32	1-11/16	AN6-22	£1.16	AN6-22A	£0.64
2-15/32	1-13/16	AN6-23	£1.54	AN6-23A	£1.79
2-19/32	1-15/16	AN6-24	£1.58	AN6-24A	£1.31
2-23/32	2-1/16	AN6-25	£7.06	AN6-25A	£1.31
2-27/32	2-3/16	AN6-26	£0.68	AN6-26A	£0.62
2-31/32	2-5/16	AN6-27	£8.08	AN6-27A	£1.54
3-3/32	2-7/16	AN6-30	£1.60	AN6-30A	£1.41
3-7/32	2-9/16	AN6-31	£1.89	AN6-31A	£4.30
3-11/32	2-11/16	AN6-32	£3.49	AN6-32A	£1.54
3-15/32	2-13/16	AN6-33	£1.49	AN6-33A	£1.08
3-19/32	2-15/16	AN6-34	£1.82	AN6-34A	£1.84
3-23/32	3-1/16	AN6-35	£4.36	AN6-35A	£1.20
3-27/32	3-3/16	AN6-36	£2.56	AN6-36A	£2.56
3-31/32	3-5/16	AN6-37	£3.08	AN6-37A	£2.38
4-3/32	3-7/16	AN6-40	£1.66	AN6-40A	£1.84
4-7/32	3-9/16	AN6-41	£1.74	AN6-41A	£3.88
4-11/32	3-11/16	AN6-42	£1.86	AN6-42A	£1.50
4-15/32	3-13/16	AN6-43	£2.75	AN6-43A	£1.82
4-19/32	3-15/16	AN6-44	£2.05	AN6-44A	£3.03
4-23/32	4-1/32	AN6-45	£3.05	AN6-45A	£3.43
4-27/32	4-3/16	AN6-46	£2.31	AN6-46A	£2.05
4-31/32	4-5/16	AN6-47	£2.62	AN6-47A	£2.86
5-3/32	4-7/16	AN6-50	£8.71	AN6-50A	£7.70
5-7/32	4-9/16	AN6-51	£8.43	AN6-51A	£8.05
5-11/32	4-11/16	AN6-52	£8.90	AN6-52A	£9.87
5-15/32	4-13/16	AN6-53	£8.43	AN6-53A	£8.43
5-19/32	4-15/16	AN6-54	£8.67	AN6-54A	£9.05
5-23/32	5-1/16	AN6-55	£8.32	AN6-55A	£8.43
5-27/32	5-3/16	AN6-56	£7.60	AN6-56A	£7.27
5-31/32	5-5/16	AN6-57	£7.97	AN6-57A	£8.43
6-3/32	5-7/16	AN6-60	£8.46	AN6-60A	£8.43

AN7 (7/16”-20)
Nominal Length	Grip Length	Drilled		Undrilled “A”
		Part No	Price	Part No	Price
23/32	1/16	AN7-5	£1.24	AN7-5A	£1.54
27/32	3/16	AN7-6	£1.54	AN7-6A	£7.70
31/32	5/16	AN7-7	POA	AN7-7A	£0.79
1-3/32	7/16	AN7-10	£1.93	AN7-10A	£3.16
1-7/32	9/16	AN7-11	POA	AN7-11A	£1.28
1-11/32	11/16	AN7-12	£1.39	AN7-12A	£1.84
1-15/32	13/16	AN7-13	£4.79	AN7-13A	£1.95
1-19/32	15/16	AN7-14	£5.16	AN7-14A	£1.54
1-23/32	1-1/16	AN7-15	£1.97	AN7-15A	£1.45
1-27/32	1-3/16	AN7-16	£3.84	AN7-16A	£1.01
1-31/32	1-5/16	AN7-17	£1.70	AN7-17A	£3.23
2-3/32	1-7/16	AN7-20	£1.25	AN7-20A	£0.91
2-7/32	1-9/16	AN7-21	£1.24	AN7-21A	£3.38
2-11/32	1-11/16	AN7-22	£1.70	AN7-22A	£2.18
2-15/32	1-13/16	AN7-23	POA	AN7-23A	£1.82
2-19/32	1-15/16	AN7-24	£2.01	AN7-24A	£2.44
2-23/32	2-1/16	AN7-25	£2.21	AN7-25A	£2.31
2-27/32	2-3/16	AN7-26	£2.13	AN7-26A	£1.70
2-31/32	2-5/16	AN7-27	£2.92	AN7-27A	£3.05
3-3/32	2-7/16	AN7-30	POA	AN7-30A	£1.93
3-7/32	2-9/16	AN7-31	£2.05	AN7-31A	£2.01
3-11/32	2-11/16	AN7-32	£2.24	AN7-32A	£3.84
3-15/32	2-13/16	AN7-33	£1.74	AN7-33A	£3.79
3-19/32	2-15/16	AN7-34	£2.44	AN7-34A	£3.00
3-23/32	3-1/16	AN7-35	£3.30	AN7-35A	£2.42
3-27/32	3-3/16	AN7-36	£2.21	AN7-36A	£2.13
3-31/32	3-5/16	AN7-37	£2.98	AN7-37A	£2.01
4-3/32	3-7/16	AN7-40	£5.19	AN7-40A	£5.07
4-7/32	3-9/16	AN7-41	POA	AN7-41A	POA
4-11/32	3-11/16	AN7-42	£5.60	AN7-42A	£3.21
4-15/32	3-13/16	AN7-43	£9.71	AN7-43A	£2.21
4-19/32	3-15/16	AN7-44	£4.18	AN7-44A	£4.04
4-23/32	4-1/32	AN7-45	£3.83	AN7-45A	£2.16
4-27/32	4-3/16	AN7-46	£3.52	AN7-46A	£3.68
4-31/32	4-5/16	AN7-47	£3.68	AN7-47A	£3.56
5-3/32	4-7/16	AN7-50	£10.02	AN7-50A	£10.72
5-7/32	4-9/16	AN7-51	POA	AN7-51A	£17.43
5-11/32	4-11/16	AN7-52	£10.79	AN7-52A	£10.21
5-15/32	4-13/16	AN7-53	£7.18	AN7-53A	£7.18
5-19/32	4-15/16	AN7-54	POA	AN7-54A	POA
5-23/32	5-1/16	AN7-55	£9.55	AN7-55A	£9.67
5-27/32	5-3/16	AN7-56	POA	AN7-56A	£11.41
5-31/32	5-5/16	AN7-57	POA	AN7-57A	£10.45
6-3/32	5-7/16	AN7-60	£11.22	AN7-60A	£10.37

AN8 (1/2”-20)
Nominal Length	Grip Length	Drilled		Undrilled “A”
		Part No	Price	Part No	Price
27/32	1/16	AN8-6	£1.07	AN8-6A	£1.25
31/32	3/16	AN8-7	£1.70	AN8-7A	£1.01
1-3/32	5/16	AN8-10	£2.05	AN8-10A	£1.25
1-7/32	7/16	AN8-11	£1.55	AN8-11A	£1.13
1-11/32	9/16	AN8-12	£2.13	AN8-12A	£1.20
1-15/32	11/16	AN8-13	£2.55	AN8-13A	£1.07
1-19/32	13/16	AN8-14	£1.66	AN8-14A	£1.49
1-23/32	15/16	AN8-15	£2.17	AN8-15A	£1.55
1-27/32	1-1/16	AN8-16	£1.66	AN8-16A	£1.25
1-31/32	1-3/16	AN8-17	£1.66	AN8-17A	£1.59
2-3/32	1-5/16	AN8-20	£2.13	AN8-20A	£1.29
2-7/32	1-7/16	AN8-21	£2.85	AN8-21A	£1.59
2-11/32	1-9/16	AN8-22	£2.55	AN8-22A	£1.86
2-15/32	1-11/16	AN8-23	£2.40	AN8-23A	£1.43
2-19/32	1-13/16	AN8-24	£1.93	AN8-24A	£3.16
2-23/32	1-15/16	AN8-25	£2.71	AN8-25A	£1.86
2-27/32	2-1/16	AN8-26	£2.40	AN8-26A	£1.82
2-31/32	2-3/16	AN8-27	£2.21	AN8-27A	£1.74
3-3/32	2-5/16	AN8-30	£3.52	AN8-30A	£2.28
3-7/32	2-7/16	AN8-31	£3.25	AN8-31A	£1.93
3-11/32	2-9/16	AN8-32	£2.63	AN8-32A	£2.48
3-15/32	2-11/16	AN8-33	£3.37	AN8-33A	£2.13
3-19/32	2-13/16	AN8-34	£2.40	AN8-34A	£2.21
3-23/32	2-15/16	AN8-35	POA	AN8-35A	£2.28
3-27/32	3-1/16	AN8-36	£2.21	AN8-36A	£2.01
3-31/32	3-3/16	AN8-37	£3.02	AN8-37A	£2.48
4-3/32	3-5/16	AN8-40	£6.15	AN8-40A	£2.52
4-7/32	3-7/16	AN8-41	£2.94	AN8-41A	£2.98
4-11/32	3-9/16	AN8-42	£3.25	AN8-42A	POA
4-15/32	3-11/16	AN8-43	£3.68	AN8-43A	£3.06
4-19/32	3-13/16	AN8-44	£3.33	AN8-44A	£4.45
4-23/32	3-15/16	AN8-45	£3.68	AN8-45A	£3.83
4-27/32	4-1/32	AN8-46	POA	AN8-46A	£15.00
4-31/32	4-3/16	AN8-47	£4.45	AN8-47A	£10.25
5-3/32	4-5/16	AN8-50	£12.77	AN8-50A	£9.26
5-7/32	4-7/16	AN8-51	POA	AN8-51A	£9.67
5-11/32	4-9/16	AN8-52	£11.57	AN8-52A	£12.92
5-15/32	4-11/16	AN8-53	£9.60	AN8-53A	POA
5-19/32	4-13/16	AN8-54	POA	AN8-54A	£13.31
5-23/32	4-15/16	AN8-55	£12.96	AN8-55A	POA
5-27/32	5-1/16	AN8-56	£9.75	AN8-56A	£12.77
5-31/32	5-3/16	AN8-57	£9.98	AN8-57A	POA
6-3/32	5-5/16	AN8-60	£11.53	AN8-60A	POA