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Standard T-Bolts Dimensions Table Chart

Engineering Hardware Standards

Standard T-Bolts ANSI/ASME B5.1M-1985 Dimensions and Tolerances Table

Nominal T-Bolt Size and Thread		Bolt Head Dimensions
		Width Across Flats				Width Corners		Height C2
inch UNC-2A	metric ISO a	inch		mm		inch max	mm max	inch		mm
		max	min	max	min			max	min	max	min
-	M4	-	-	9	8.5	-	12.7	-	-	2.5	2.1
-	M5	-	-	10	9.5	-	14.1	-	-	-	3.6
0.250 - 20	M6	0.469	0.438	13	12	0.663	18.4	0.156	0.141	4 6	5.6
0.312 - 18	M8	0.562	0.531	15	14	0.796	21.2	0.188	0.172	6	5.6
0.375 - 16	M10	0.688	0.656	18	17	0.972	25.5	0.250	0.234	7	6.6
0.500 - 13	M12	0.875	0.844	22	21	1.238	31.1	0.312	0.297	8	7.6
0.625 - 11	M16	1.125	1.094	28	27	1.591	39.6	0.406	0.391	10	9.6
0.750 - 10	M20	1.312	1.281	34	33	1.856	48.1	0.531	0.500	14	13.2
1.000 - 8	M24	1.688	1.656	43	42	2.387	60.8	0.688	0.656	18	17.2
1.250 - 7	M30	2.062	2.031	53	52	2.917	75	0.938	0.906	23	22.2
1.500 - 6	M36	2.500	2.469	64	63	3.536	90.5	1.188	1.156	28	27.2
-	M42	-	-	75	74	-	106.1	-	-	32	30.5
-	M48	-	-	85	84	-	120.2	-	-	36	34.5

a. Corners of T-bolts may be square or may be rounded or broken to the indicated maximum dimensions at the manufacturer's option. d Metric thread grade and tolerance position is 5g 6g

Nominal T-Bolt Size and Thread		Radius of Corners
		R2		W2
inch UNC-2A	metric ISO a	inch max	mm max	inch max	mm max
-	M4	-	0.3	-	0.5
-	M5	-	0.3	-	0.5
0.250 - 20	M6	0.02	0.5	0.03	0.8
0.312 - 18	M8	0.02	0.5	0.03	0.8
0.375 - 16	M10	0.02	0.5	0.03	0.8
0.500 - 13	M12	0.02	0.5	0.06	1.5
0.625 - 11	M16	0.03	0.8	0.06	1.5
0.750 - 10	M20	0.03	0.8	0.06	1.5
1.000 - 8	M24	0.03	0.8	0.06	1.5
1.250 - 7	M30	0.03	0.8	0.06	1.5
1.500 - 6	M36	0.03	0.8	0.06	1.5
-	M42	-	1	-	2
-	M48	-	1	-	2