This is a Manufacturer Approved replacement nut for lawn and garden equipment. This item is Metal an is Sold Individually. A lock nut is a type of nut that resists loosening when properly threaded onto a bolt.
This is an original replacement part manufactured for use with riding lawnmowers. The washer is used with several different models of lawnmowers and has multiple applications depending on the model of the mower. This washer is available as an individual replacement part, please see model diagram for part location and usage.
This is an authentic OEM component from Husqvarna. The hex cap screw 5/16-18 X 1 is constructed of heavy-duty metal, and is sold individually. This item often helps to secure various components in lawn tractors. You will need a wrench for the repair.