All Metal Lock Nuts, Grade C – Collar Style Sizes 1 1/8" to 2"
Earnest line of "All Metal Lock Nuts” in sizes 1/4” to 1” are made to what is commonly called the “automation” style or “stover” style with a crowned top that is crimped to create the locking feature. The dimensions and locking ability are designed to meet the requirements of the Industrial Fastener Institutes (IFI) standard for "Prevailing Torque" style lock nuts (IFI Standard 100/107). This line is through hardened to a Grade C strength level (150,000 psi min Proof Load Strength). Grade C nuts are designed to be used with threaded fasteners of strengths up to the Grade 8 (per SAE J429).
The prevailing torque is generated by the controlled crimp that is applied to the crowned area on top of the nut. The crimped area is designed to develop uniform holding power on the male thread, without creating excessive interference, to provide excellent resistance to loosening in high vibration applications. Nuts are plated with an electroplated zinc and clear chromate and have a wax added to provide uniform torque tension performance along with corrosion protection (other platings are available upon request).
Physical Properties of Grade C Nuts
Proof Load Strength 150,000 psi min
Rockwell Hardness Rc 26/36
| Size |
Width
Across |
Total
Thickness |
Hex
Height |
| F |
H |
J |
| Max |
Min |
Max |
Min |
Min |
| 1/4 |
.438 |
.428 |
.288 |
.212 |
.145 |
| 5/16 |
.502 |
.489 |
.336 |
.258 |
.166 |
| 3/8 |
.564 |
.551 |
.415 |
.320 |
.198 |
| 7/16 |
.689 |
.675 |
.463 |
.365 |
.223 |
| 1/2 |
.752 |
.736 |
.573 |
.427 |
.262 |
| 9/16 |
.877 |
.861 |
.621 |
.473 |
.286 |
| 5/8 |
.939 |
.922 |
.731 |
.535 |
.329 |
| 3/4 |
1.127 |
1.088 |
.872 |
.617 |
.382 |
| 7/8 |
1.314 |
1.269 |
.922 |
.831 |
.513 |
| 1" |
1.502 |
1.450 |
1.018 |
.831 |
.513 |