Hex Jam Nuts: Dimensions & Technical Information

Heavy Hex Nut Drawing & Dimensions

Hex Jam Nuts: Dimensions (ANSI/ASME B18.2.2-1987)

Nominal or Basic Major Diameter of Thread

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 Width Across Flats (F)

 Width Across Corners (G) Thickness of Hex Jam Nuts (H) 
Basic Max Min  Max  Min Basic  Max Min 
1/4 0.2500 7/16 .438 .428 .505 .488 5/32 0.163 0.150
5/16 0.3125 1/2 .500 .489 .577 .557 3/16 0.195 0.180
3/8 0.3750 9/16 .562 .551 .650 .628 7/32 0.227 0.210
7/16 0.4375 11/16 .688 .675 .794 .768 1/4 0.260 0.240
1/2 0.5000 3/4 .750 .736 .866 .840 5/16 0.323 0.302
9/16 0.5625 7/8 .875 .861 1.010 .982 5/16 0.324 0.301
5/8 0.6250 15/16 .938 .922 1.083 1.051 3/8 0.387 0.363
3/4 0.7500 1-1/8 1.125 1.088 1.299 1.240 24/64 0.446 0.398
7/8 0.8750 1-5/16 1.312 1.269 1.516 1.447 31/64 0.510 0.458
1 1.0000 1-1/2 1.500 1.450 1.732 1.653 35/64 .575 0.519
1-1/8 1.1250 1-11/16 1.688 1.631 1.949 1.859 39/64 .639 .579
1-1/4 1.2500 1-7/8 1.875 1.812 2.165 2.066 23/32 .751 .687
1-3/8 1.3750 2-1/16 2.062 1.994 2.382 2.273 25/32 .815 .747
1-1/2 1.5000 2-1/4 2.250 2.175 2.598 2.480 27/32 .880 .808
1-3/4 1.7500 2-5/8 2.625 2.538 3.031 2.893 31/32 1.009 .929
2 2.000  3 3.000 2.900 3.464 3.306 1-3/32 1.138 1.050
2-1/4 2.2500 3-1/2 3.500 3.388 4.041 3.862 1-13/64 1.251 1.155
2-1/2 2.5000 3-7/8 3.875 3.750 4.474 4.275 1-29/64 1.505 1.401

 

Hex Jam Nuts: Performance & Mechanical Specs
Description A six-sided internally threaded fastener that is 2/3 the thickness of a standard full form nut.
Applications Jam nuts are used with finished or heavy hex nuts to keep them from loosening. The jam nut is placed against the work surface and then the hex nut or heavy hex nut is applied.
Material

Steel Hex Jam Nuts are made from a low carbon with the following properties: Carbon: 0.47% max; Phosphorus: 0.12% max; Sulfur: 0.23% max

Stainless Steel Hex Jam Nuts are made from one of the following austenitic alloys: 303, 303Se, 304, XM7, all of which have chromium content of 18% and a nickel content of 8%.
Core Hardness

Steel: Rockwell B68-C32

Stainless Steel: Rockwell B95-C32
Proof Load 

Steel: Coarse Thread - 54,000 psi, Fine Thread - 48,000 psi

Stainless Steel: 1/4" - 1/2" - 60,000
Heavy Hex Jam Nuts: Dimensions (ANSI/ASME B18.2.2-1987 - R 1999)

Nominal or Basic Major Diameter of Thread

 		 Width Across Flats (F) Width Across Corners (G) Thickness of Heavy Hex Jam Nuts (H) 
Max Min  Max  Min  Max Min 
1/4 .500 .488 .577 .556 0.188 0.156
5/16 .562 .546 .650 .622 0.220 0.186
3/8 .688 .669 .794 .763 0.252 0.216
7/16 .750 .728 .866 .830 0.285 0.247
1/2 .875 .850 1.010 .969 0.371 0.277
9/16 .938 .909 1.083 1.037 0.349 0.307
5/8 1.062 1.031 1.227 1.175 0.381 0.337
3/4 1.250 1.212 1.443 1.382 0.446 0.398
7/8 1.438 1.394 1.660 1.589 0.510 0.458
1 1.625 1.575 1.876 1.796 .575 0.519
1-1/8 1.812 1.756 2.093 2.002 .639 .579
1-1/4 2.000 1.938 2.309 2.209 .751 .687
1-3/8 2.188 2.119 2.526 2.416 .815 .747
1-1/2 2.375 2.300 2.742 2.622 .880 .808
1-3/4 2.750 2.662 3.175 3.035 1.009 .929
2 3.125 3.025 3.608 3.449 1.138 1.050

 

Heavy Hex Jam Nuts: Performance & Mechanical Specs
Description A six-sided internally threaded fastener that is 2/3 the thickness of a heavy hex nut.
Applications Jam nuts are used with heavy hex nuts to keep them from loosening. The jam nut is placed against the work surface and then the heavy hex nut is applied.