Gibraltar 34038 Locking Knob Handle Plunger 1/2-13

Product Description

The GIBRALTAR 34038 is a locking-style knob handle plunger designed for use in positioning, clamping, and indexing applications on industrial machinery, fixtures, and tooling setups. This threaded stud plunger features a 1/2-13 thread size with a 7/8-inch thread length and delivers an initial end force of 1.25 pounds ramping to a final end force of 5 pounds. The plunger diameter measures 0.249 inches with a tolerance of plus 0.001 inches, and the plunger projection extends 0.25 inches. Constructed from steel with a zinc-plated finish, the 34038 provides corrosion resistance for demanding shop and production environments. It ships as a knobless threaded stud, making it compatible with customer-supplied or separately sourced knobs.

The GIBRALTAR 34038 is suited for light- to medium-duty machine tool, fixture, and jig applications where a repeatable locking plunger action is required. The threaded stud configuration allows direct installation into tapped holes in steel, aluminum, or cast components. With a stud thread size of 3/8-16 and a length under head/shoulder of 1.125 inches, this plunger integrates into standard tooling plate and fixture designs. It is commonly installed by machine builders, maintenance machinists, and tooling technicians in production and job-shop environments.

Key Features

• Locking plunger element holds position under load without backing out
• 1/2-13 main thread with 7/8-inch thread length for secure engagement
• 3/8-16 stud thread size for direct installation into tapped fixture components
• Initial end force of 1.25 pounds rising to 5 pounds final end force
• Steel construction with zinc-plated finish for corrosion resistance
• Knobless threaded stud design accepts separately sourced or customer-supplied knobs

Compatibility

Designed as an OEM-style replacement or direct-fit component for industrial fixtures, tooling plates, and machine tool assemblies requiring a 1/2-13 locking plunger with a 3/8-16 stud thread.

Installation Notes

Installation is performed by machinists or tooling technicians using standard hand tools. Ensure the receiving tapped hole is clean and matches the 3/8-16 stud thread specification before installation. De-energize or lock out any associated machinery per OSHA lockout/tagout procedures prior to installing or replacing plunger hardware. Do not exceed the rated final end force of 5 pounds, as over-compression may damage the locking element.