ASME B18.2.1 dimensions — Hex cap screws, inch series (Table 6 profile)

Name: ASME B18.2.1 dimensions
Creator: TaurusFix

Edition: 2012 (R2021) edition, current
Related: ASME B1.1-2024ASTM A307ASTM F593

Hex Cap Screw ASME B18.2.1In stock · 143 sizesView product

ASME B18.2.1 dimensions

in · 28 sizes, 1/4-20 UNC – 1-1/2-12 UNFIn stock

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Size	TPIThreads per inch	FWidth across flats		HHead height		GWidth across corners		Basic major diameter	Thread series	Thread class	EBody diameter		LTThread length		JWrenching height
Size		min	max	min	max	min	max				min	max	nom. L≤6 in	nom. L>6 in	min
1/4-20 UNC	20	0.428	0.438	0.15	0.163	0.488	0.505	0.25	UNC	2A	0.245	0.25	0.75	1	0.106
1/4-28 UNF	28	0.428	0.438	0.15	0.163	0.488	0.505	0.25	UNF	2A	0.245	0.25	0.75	1	0.106
5/16-18 UNC	18	0.489	0.5	0.195	0.211	0.557	0.577	0.3125	UNC	2A	0.3065	0.3125	0.875	1.125	0.14
5/16-24 UNF	24	0.489	0.5	0.195	0.211	0.557	0.577	0.3125	UNF	2A	0.3065	0.3125	0.875	1.125	0.14
3/8-16 UNC	16	0.551	0.562	0.226	0.243	0.628	0.65	0.375	UNC	2A	0.369	0.375	1	1.25	0.16
3/8-24 UNF	24	0.551	0.562	0.226	0.243	0.628	0.65	0.375	UNF	2A	0.369	0.375	1	1.25	0.16
7/16-14 UNC	14	0.612	0.625	0.272	0.291	0.698	0.722	0.4375	UNC	2A	0.4305	0.4375	1.125	1.375	0.195
7/16-20 UNF	20	0.612	0.625	0.272	0.291	0.698	0.722	0.4375	UNF	2A	0.4305	0.4375	1.125	1.375	0.195
1/2-13 UNC	13	0.736	0.75	0.302	0.323	0.84	0.866	0.5	UNC	2A	0.493	0.5	1.25	1.5	0.215
1/2-20 UNF	20	0.736	0.75	0.302	0.323	0.84	0.866	0.5	UNF	2A	0.493	0.5	1.25	1.5	0.215
9/16-12 UNC	12	0.798	0.812	0.348	0.371	0.91	0.938	0.5625	UNC	2A	0.5545	0.5625	1.375	1.625	0.25
9/16-18 UNF	18	0.798	0.812	0.348	0.371	0.91	0.938	0.5625	UNF	2A	0.5545	0.5625	1.375	1.625	0.25
5/8-11 UNC	11	0.922	0.938	0.378	0.403	1.051	1.083	0.625	UNC	2A	0.617	0.625	1.5	1.75	0.269
5/8-18 UNF	18	0.922	0.938	0.378	0.403	1.051	1.083	0.625	UNF	2A	0.617	0.625	1.5	1.75	0.269
3/4-10 UNC	10	1.1	1.125	0.455	0.483	1.254	1.299	0.75	UNC	2A	0.741	0.75	1.75	2	0.324
3/4-16 UNF	16	1.1	1.125	0.455	0.483	1.254	1.299	0.75	UNF	2A	0.741	0.75	1.75	2	0.324
7/8-9 UNC	9	1.285	1.312	0.531	0.563	1.465	1.516	0.875	UNC	2A	0.866	0.875	2	2.25	0.378
7/8-14 UNF	14	1.285	1.312	0.531	0.563	1.465	1.516	0.875	UNF	2A	0.866	0.875	2	2.25	0.378
1-8 UNC	8	1.469	1.5	0.591	0.627	1.675	1.732	1	UNC	2A	0.99	1	2.25	2.5	0.416
1-12 UNF	12	1.469	1.5	0.591	0.627	1.675	1.732	1	UNF	2A	0.99	1	2.25	2.5	0.416
1-1/8-7 UNC	7	1.631	1.688	0.658	0.718	1.859	1.949	1.125	UNC	2A	1.114	1.125	2.5	2.75	0.461
1-1/8-12 UNF	12	1.631	1.688	0.658	0.718	1.859	1.949	1.125	UNF	2A	1.114	1.125	2.5	2.75	0.461
1-1/4-7 UNC	7	1.812	1.875	0.749	0.813	2.066	2.165	1.25	UNC	2A	1.239	1.25	2.75	3	0.53
1-1/4-12 UNF	12	1.812	1.875	0.749	0.813	2.066	2.165	1.25	UNF	2A	1.239	1.25	2.75	3	0.53
1-3/8-6 UNC	6	1.994	2.062	0.81	0.878	2.273	2.382	1.375	UNC	2A	1.363	1.375	3	3.25	0.569
1-3/8-12 UNF	12	1.994	2.062	0.81	0.878	2.273	2.382	1.375	UNF	2A	1.363	1.375	3	3.25	0.569
1-1/2-6 UNC	6	2.175	2.25	0.902	0.974	2.48	2.598	1.5	UNC	2A	1.488	1.5	3.25	3.5	0.64
1-1/2-12 UNF	12	2.175	2.25	0.902	0.974	2.48	2.598	1.5	UNF	2A	1.488	1.5	3.25	3.5	0.64

Dimensions from ASME B18.2.1-2012 (R2021), the current edition.

ASME B18.2.1 sizes

1/4-20 UNC16 5/16-18 UNC18 3/8-16 UNC19 7/16-14 UNC18 1/2-13 UNC18 5/8-11 UNC15 3/4-10 UNC14 7/8-9 UNC13 1-8 UNC12 All 143 sizes in this family →