CALIFORNIA WARNING: This product can expose you to chemicals, including lead and DEHP, which are known to the State of California to cause cancer and birth defects, or other reproductive harm. For more information, go to https://www.p65warnings.ca.gov.
Zinc-plated grade 2 steel thin hex jam nut. A jam nut is generally half as tall as a standard nut. When a standard nut is too tall, a jam nut can be used. It also functions as a lock nut where it is jammed against a standard nut to lock the two in place.
Dimensions: 3/8 inch-24 thread size, 9/16" width, 7/32" height.
Reference:
4422-01135-00