Description
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. It’s 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 (12.9) Steel
- Hex Head Type
- 1-inch Length
- Fits GM V6, SB 265-400, Buick, Olds, Pontiac '79 and earlier, Mopar BB 383-440 exc 413, AMC V8's w 3/8" bolts
- Sold as Set of 12
Specifications :
Brand: Proform Parts
Manufacturer's Part Number: 66753
Part Type: Header Fasteners
Product Line: Proform Self-Locking Wedge Header Bolts
Fastener Style: Bolt
Thread Size: 3/8 in.-16
Head Style: Hex
Underhead Length (in.): 1.000 in.
Fastener Material: Steel
Fastener Color: Black oxide
Quantity: Sold as a set of 12.