Poulan 521991102  NUT 1/2-13 HEX FLANGE NYLOK CL

A Nut is a type of fastener with a threaded hole, used in conjunction with a bolt to fasten multiple parts together. Be sure to tighten nuts to the appropriate torque setting, and select the appropriate graded strength of the nut, compatible with the bolt. While some nuts look almost identical to ones you find in a hardware store, other types, like a spring nut or an insert nut, are uniquely built for their purpose and should be purchased from a genuine OEM parts dealer, like us, to ensure safe operation.