Serrated Flange Screws, Hex Flange Lock Bolts, or Whiz-lock Bolts are designed with a built-in washer underneath the head of the bolt — distributing the clamping load over a wider area. This eliminates the need for a separate washer, as it provides the same holding power. Engineered with quality in mind, Zirks' Flange Bolts are made to Property Class 10.9 standard to provide the durability and strength. These two-in-one bolts are popularly used to secure truck frames with ease, as well as many other applications.

Serrated Flange (Whiz-Lock™ Bolt, Whiz-Lock™ Screw) – Grade 8 and 120M case hardened

Built-in serrated washers prevent loosening in high-vibration applications
Teeth lock the bolt and stop it from backing out
120M case-hardened bolt creates durable teeth that won’t wear out
Grade 8 are through hardened to Rockwell hardness of Rc 33/39
Diameter sizes range from 1/4” to 5/8”
Meets ASME B18.2.1 standards

Serrated Flange Screws, Hex Flange Lock Bolts, or Whiz-lock Bolts are designed with a built-in washer underneath the head of the bolt — distributing the clamping load over a wider area. This eliminates the need for a separate washer, as it provides the same holding power. Engineered with quality in mind, Zirks' Flange Bolts are made to Property Class 10.9 standard to provide the durability and strength. These two-in-one bolts are popularly used to secure truck frames with ease, as well as many other applications.

Serrated Flange (Whiz-Lock™ Bolt, Whiz-Lock™ Screw) – Grade 8 and 120M case hardened

Built-in serrated washers prevent loosening in high-vibration applications
Teeth lock the bolt and stop it from backing out
120M case-hardened bolt creates durable teeth that won’t wear out
Grade 8 are through hardened to Rockwell hardness of Rc 33/39
Diameter sizes range from 1/4” to 5/8”
Meets ASME B18.2.1 standards