Gibraltar 31332SG Steel Thumb Screw 5/16-18 Knurled

Product Description

The GIBRALTAR 31332SG is a steel thumb screw with a knurled head, designed for tool-free manual adjustment in industrial, mechanical, and assembly applications. It features a 5/16-18 UNC thread and a swivel pad tip that pivots up to 20 degrees, allowing the fastener to seat firmly against angled or irregular surfaces without marring them. The black oxide finish provides moderate corrosion resistance and reduces light reflection in precision environments. At 0.14 pounds, this is a compact, single-piece fastener suited for frequent hand-adjustment cycles where a conventional hex or socket fastener would be impractical.

This thumb screw is used in jigs, fixtures, machine tool setups, workholding applications, and general industrial assembly wherever repeatable manual clamping or positioning is needed. The swivel pad tip makes it particularly well-suited for setups where the clamping surface is not perpendicular to the screw axis. It is installed and adjusted by hand without tooling, making it appropriate for production environments, tooling rooms, and fabrication shops. Machinists, toolmakers, and assembly technicians are the typical end users.

Key Features

• 5/16-18 UNC thread for wide compatibility with standard tapped holes
• Knurled head allows secure hand grip for tool-free adjustment
• Swivel pad tip pivots up to 20 degrees to accommodate angled clamping surfaces
• Black oxide finish for corrosion resistance and reduced glare
• Steel construction throughout, including the swivel tip, for durability under clamping load
• No-shoulder design for straightforward thread engagement

Compatibility

Designed as a standard UNC thumb screw replacement or upgrade for 5/16-18 tapped holes in jigs, fixtures, and industrial workholding equipment.

Installation Notes

No tools are required for installation or adjustment under normal hand-tightening use. Verify that the mating tapped hole meets 5/16-18 UNC thread standards before installation. Do not exceed the manual torque achievable by hand, as over-torquing with a wrench can damage the knurled head or swivel pad assembly. Inspect the swivel pad periodically for wear if used in high-cycle clamping applications.