5/16"-18 x 9/16" 18-8 Stainless Jam Nuts (15 pcs.)

Diameter: 5/16"
Diameter 2: 9/16"
Thickness: 3/16"
Material: Stainless Steel
Driver Type: 1/2" Wrench
Thread Size: 18 (Coarse)
Shape: Jam Nut
Hardness: 18-8
Type: Jam Nut

Box of 15.

A jam nut is a low profile type of nut, typically half as tall as a standard nut. It is commonly used as a type of locknut, where it is "jammed" up against a standard nut to lock the two in place. It is also used in situations where a standard nut would not fit.