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
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 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