Each PROFORM Grade 8 Header Bolt is permanently assembled with a pair of special washers. When the bolt is torqued to 28+ ft-lbs, the washers super-hardened external teeth bite into and grip the bottom of the bolt head and the top surface of the header. After being self-locked in this manner, any bolt-loosening rotation is blocked by a wedge-locking action created by the washers interfacing, matching cams. Its an uphill climb: vibration that might ordinarily loosen the bolt actually increases the wedge-locking tension, securing the bolt even more. Because this simple wedge-locking method uses tension instead of friction, contact with oil actually facilitates the wedge effect. When changing headers, PROFORM Header Bolts can be untightened with a normal wrench, lubricated, and reused.

Features:
Grade 8 Steel
  • Hex Head Type
  • 1-inch Length
  • Fits Select 16 Bolt 3/8" Diameter Applications
  • PROFORM Parts Brand Product
  • Sold as Set of 16
  • More From This Category

    Proform , Hi-Torque Mini Nuts , Chrome; No Logos; 1/4"-20 Thread

    Proform , Hi-Torque Mini Nuts , Chrome; No Logos; 1/4"-20 Thread

    $20.60

    Proform , Buick 455 Starter 2.2KW; 15:1 Ratio, Fits Buick 455 Engines

    Proform , Buick 455 Starter 2.2KW; 15:1 Ratio, Fits Buick 455 Engines

    $476.86

    Proform , Chevrolet Big-Block Slant-Edge Valve Covers, Chrome; Tall; Recessed Red/Black Emblems

    Proform , Chevrolet Big-Block Slant-Edge Valve Covers, Chrome; Tall; Recessed Red/Black Emblems

    $882.29

    Proform , Carburetor Studs Kit w/ Lock Washers & Nuts, Chrome Plated; Made from High-Quality Steel

    Proform , Carburetor Studs Kit w/ Lock Washers & Nuts, Chrome Plated; Made from High-Quality Steel

    $14.65