K-Lock nuts
Material:   Steel / Stainless Steel  

Made from carbon steel with a heat treated external star washer attached, these nuts will bite into a soft surface while torquing, providing a locking action. Zinc plating is standard. Sizes from #4 to 3/8"

We are a professional and leading manufacture of all kinds of standard and non-standard fasteners according to your requirement in China.
Standard: GB; ISO; DIN;ANSI;BS;JIS
Product: nuts; screws; bolts; rivets; washers; nails; pins, non-standard pieces.
We are very confident that we can satisfy you with good quality and best price .Looking forward to cooperating with you.

A Keps nut, also called a K-nut^[1] or washer nut, is a nut with an attached, free-spinning washer. It is used to make assembly more convenient. Common washer types are star-type lock washers, conical, and flat washers.^[1]