A Hill Lock® screw is a free running screw that locks itself in place with serrations or locking teeth under the head. The most popular style of Hill-Lock® is an indented flange head.

The bearing surface of the flange affords a larger locking area for better performance. It is like a hex screws and lock-washer combination all in one piece.

All Hill Fastener products are traceable, back to the specific heat lot of steel used in the manufacturing process. Material, chemical and physical certificates are kept on file and can be provided upon request. Inspection is performed during each phase of production and the documentation becomes part of the permanent file. If requested before production, a certification to a specific requirement can be provided by Hill Fastener's Laboratory along with shipment.

A frame bolt is a Grade-8 indented hex flange screw with a recessed fillet radius. This added feature improves joint integrity by providing a more uniform bearing surface with drilled or punched holes. Most truck and auto rebuilders prefer this undercut feature to the O.E.M. product.

Hill Fastener provides them from high-grade alloy steel to meet or exceed 150,000 p.s.i. tensile strength.

Hill Fastener Corporation owns two distinct markings; our logo "H" made from a nut and bolt, and a stylized "HF."

These markings are registered with the U.S. Patent and Trademark Office, and recoreded with the U.S. Department of Commerce in compliance with "The Fastener Quality Act."