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- BrochureA= 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 |
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 |
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 |
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 | -- | -- | -- | -- |
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 |
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 |
© 2013 Duncan Bolt