The nut is a critical component in the majority of fastener applications. The quality of the nut is as crucial as the quality of the bolt it will be paired with. Correct and proper clamp load, essential to ensure the assembly will withstand the working loads required, can only be achieved if the nut is concentric and rotates freely. There is no room for error.

Earnest Machine Products testing lab is fully equipped to test and verify all the critical feature of a hex nut to ensure proper performance. Shown below are some of the key features that our lab sees from manufacturers that do not maintain the high quality standards.

HIGH QUALITY PRODUCT

POOR QUALITY PRODUCT

Concentricity of threads to nut body: Centering the threads to the body of the nuts is essential for proper torque tension performance. Poor quality nuts have holes that are not tapped concentric to the hex body. Non-concentric tapped holes create added strain to the bolt during assembly.

Perpendicularity of threads to bearing face: Threads that are not tapped at a right angleto the bearing face will result in bending strain in the bolt which can result in premature failures.

Bearing Surface Smoothness: Rough bearing faces prevent proper clamp loads from being developed in the assembly.

Nut Form: Poorly formed hex corners cause wrench slippage and weaken the hoop strength of the nut.