The Huck BobTail® Fastener System- Inch Series

Engineered for the highest level of performance and reliability.

Dimensional and grip data for small and large diameter inch sizes are below. Click here for BobTail- Metric.

Installed values and tooling information can be found in the attached brochures.

Download: Small Diameter BobTail- Brochure           Download: Large Diameter BobTail- Brochure

Small Diameter Dimensions

A= Diameter / B= Head Dimension / C= Head Height

		Trazier Head		98T Head		90° Head
Diameter (A)		B	C	B	C	B	C
3/16 (6)	.187 max	--	--	.488 - .468	.110 - .090	.354 - .328	.085 - .075
1/4 (8)	.549 max	.537 - .507	.140 - .120	--	--	.473 - .437	.113 -.104
5/16 (10)	.313 max	.380 - .640	.175 - .150	--	--	.589 - .547	.141 - .127
3/8 (12)	.374 max	.820 - .780	.210 - .190	--	--	.709 - .656	.168 - .152

Grip Table

D= Shank / E= Length under Head

Grip	Grip Range	3/16 (6)		1/4 (8)		5/16 (10)		3/8 (12)
		D	E	D	E	D	E	D	E
4	.125 - .375	.187	.838	.187	1.000	.187	1.156	.187	1.310
6	.250 - .500	.312	.960	.312	1.125	.312	1.281	.312	1.435
8	.375 - .625	.437	1.085	.437	1.250	.437	1.406	.437	1.560
10	.500 - .750	.562	1.210	.562	1.375	.562	1.531	.562	1.685
12	.625 - .875	.687	1.335	.687	1.500	.687	1.656	.687	1.810
14	.750 - 1.00	.812	1.460	.812	1.625	.812	1.781	.812	1.935
16	.875 - 1.125	.937	1.585	.937	1.750	.937	1.906	.937	2.060
18	1.00 - 1.25	1.062	1.710	1.062	1.875	1.062	2.031	1.062	2.185
20	1.125 - 1.375	1.187	1.835	1.187	2.000	1.187	2.156	1.187	2.310

Collar Dimensions

F= Flange Diameter / G= Height / H= Outside Diameter / J = Inside Diameter

Diameter	F	G	H	J
3/16	.370 - .390	.270 - .290	.287 max	.187 - .192
1/4	.485 - .515	.360 - .380	.396 max	.250 - .255
5/16	.610 - .640	.458 - .478	.500 max	.316 - .322
3/8	.730 - .770	.545 - .562	.600 max	.376 - .384

Large Diameter Dimensions

A= Diameter / B= Head Dimension / C= Head Height

		Round Head		Flanged Head		Stainless Steel Cap
Diameter (A)		B	C	B	C	B	C
1/2	.500 max	.953 - .861	.297 - .335	--	--	--	--
5/8	.625 max	1.086 - 1.196	.367 - .432	1.270 - 1.330	.448 - .499	1.270 - 1.330	.300 - .340
3/4	.750 max	1.325 - 1.440	.455 - .530	1.520 - 1.660	--	--	--
7/8	.875 max	1.540 - 1.665	.525 - .585	--	--	--	--
1	1.000 max	1.750 - 2.000	.590 - .650	--	--	--	--

Grip Table

D= Shank / E= Length under Head

Grip	Grip Range	1/2		5/8		3/4		7/8		1
		D	E	D	E	D	E	D	E	D	E
4	.25 - .62	.150	1.440	.150	1.601	.160	1.850	.250	2.056	.250	2.260
8	.50 - .87	.150	1.690	.150	2.101	.160	2.100	.250	2.306	.250	2.510
12	.75 - 1.12	.150	1.940	.150	2.101	.160	2.350	.250	2.556	.250	2.760
16	1.00 - 1.37	.150	2.190	.150	2.351	.160	2.600	.250	2.806	.250	3.010
20	1.25 - 1.62	.150	2.440	.150	2.601	.160	2.850	.250	3.056	.250	3.260
24	1.50 - 1.87	.150	2.690	.150	2.851	.160	3.100	.250	3.306	.250	3.510
28	1.75 - 2.12	.150	2.940	.150	3.101	.160	3.350	.250	3.556	.250	3.760
32	2.00 - 2.37	.150	3.190	.150	3.351	.160	3.600	.500	3.806	.500	4.010
36	2.25 - 2.62	.150	3.440	.150	3.601	.160	3.850	.500	4.056	.500	4.260
40	2.50 - 2.87	.150	3.690	.150	3.851	.375	4.100	.500	4.306	.500	4.510
44	2.75 - 3.12	.150	3.940	.375	4.101	.375	4.350	.500	4.556	.500	4.760
48	3.00 - 3.37	.375	4.190	.375	4.351	.375	4.600	.500	4.806	.500	5.010
52	3.25 - 3.62	.375	4.440	--	--	.375	4.850	.500	5.056	.500	5.260
56	3.50 - 3.87	.375	4.690	--	--	.375	5.100	.500	5.306	.500	5.510
60	3.75 - 4.12	.375	4.940	--	--	.375	5.350	.500	5.556	.500	5.760
64	4.00 - 4.37	--	--	--	--	.375	5.600	.500	5.86	.500	6.010
68	4.25 - 4.62	--	--	--	--	.375	5.850	.500	6.056	.500	6.260
72	4.50 - 4.87	--	--	--	--	.375	6.100	.500	6.306	.500	6.510

Collar Dimensions

F= Flange Diameter / G= Height / H= Outside Diameter / J = Inside Diameter

Diameter	F	G	H		J
			Grade 5	Grade 8
1/2	1.101 - 1.080	.728 - .748	.749 - .759	.762 - .772	.506 - .518
5/8	1.270 - 1.330	.912 - .932	.485 - .515	.953 - .963	.633 - .645
3/4	1.520 - 1.600	1.095 - 1.115	1.132 - 1.142	1.145 - 1.155	.760 - .774
7/8	1.775 - 1.865	1.280 - 1.300	1.310 - 1.325	--	.885 - .900
1	.930 - 2.010	1.460 - 1.490	1.500 - 1.515	1.525 - 1.540	1.010 - 1.030