Jam Nut, 1-1/4"-12 TPI Left Hand

1-1/4"-12 left hand threaded jam nut.  This is the thread you'll typically find on 1-1/4" heims.  Get the kit to include a serrated Belleville spring lock washer.  The Belleville washer will prevent the jam nut from coming loose.

Jam nuts are an important component.  They keep the primary component (heim joint or tie rod end) from spinning.  They are NOT however a nut that should be used to fasten.  They work fine for their intended purpose, but sometimes they are misused and treated like a normal nut.  They are made thinner than a typical fastening nut, and the likelihood of thread tear out when used in a fastener application is higher.