Grade GT Flange Style Lock Nuts

Nominal Size or Basic Major Thread Diameter	F			B	H		A	K
	Width Across Flats			Flange Diameter	Overall Thickness		Hex Height	Flange Thickness
	Nom	Max	Min	Max	Max	Min	Min	Min
1/4	7/16	.4385	.428	.560	.300	.265	.140	.040
5/16	1/2	.5020	.489	.680	.365	.320	.170	.050
3/8	9/16	.5645	.551	.810	.425	.404	.200	.060
7/16	11/16	.6895	.675	.930	.495	.457	.230	.070
1/2	3/4	.7520	.736	1.070	.555	.500	.260	.080
5/8	15/16	.9395	.922	1.330	.690	.646	.320	.100
3/4	1-1/8	1.1280	1.088	1.585	.825	.742	.380	.110
Product standards require all grade-marked nuts 1/4 inch and larger to have a raised or depresses insignia identifying its manufacturer. The X on the image above represents one such location.

Grade GT Flange Style Lock Nuts Properties

Description	An all metal, one-piece flanged hex nut which gets its prevailing torque characteristics from controlled distortion of its top threads from their normal helical form to a more elliptical shape.
Applications & Advantages	Has a lower, more uniform bearing stress to clamp force ratio. This style reduces inventory (by eliminating a washer) and in-place cost. It is designed specifically for use with, but not exclusively, grade-8 frame bolts.
Material	C1022 - 1045 steel
Heat Treatment	Heated to the austenitizing temperature of the material and quenched in the proper medium to obtain a predominately martensitic microstructure, and tempered to the specified hardness.
Hardness	1/4 thru 5/8 inch: Rockwell C24 - C32 3/4 thru 1 inch: Rockwell C26 - C34 1/4 thru 5/8 inch: Rockwell C26 - C36
Proof Load	150,000 psi
Plating	See plating page for plating information of steel nuts.