Jergens 21104 Lobed Knob 4-point Aluminum 1/4-20

Product Description

The JERGENS 21104 is a 4-point lobed knob machined from 319-grade aluminum, designed for hand-tightening and manual adjustment applications across industrial, mechanical, and trade equipment. With a 1-1/4 inch head diameter and a 1/4-20 threaded stem, this knob provides positive grip and controlled torque without tools. The compact overall height of 3/4 inch and 5/16 inch head thickness make it suitable for installations with limited clearance. Machinists, assemblers, and field technicians install this type of knob on panels, fixtures, jigs, enclosures, and adjustable mechanical assemblies where frequent repositioning is required.

This lobed knob fits standard 1/4-20 threaded fastener applications in light industrial and mechanical assembly settings. The 1/2 inch thread length accommodates typical panel and fixture thicknesses. Its aluminum construction keeps weight low at 0.02 pounds, making it appropriate for applications where mass is a consideration. The 4-lobe profile distributes finger pressure evenly across contact points, reducing operator fatigue during repeated adjustments. Suitable for both production floor equipment and field-serviceable assemblies.

Key Features

• 4-point lobed profile for secure, tool-free hand tightening
• 319-grade aluminum construction - lightweight and corrosion resistant
• 1/4-20 threaded hole with 1/2 inch thread depth for standard fastener compatibility
• 1-1/4 inch head diameter with 5/16 inch head height for low-profile fitment
• 9/16 inch hub diameter and 3/4 inch overall height for compact installations

Compatibility

Designed for use in any application requiring a 1/4-20 threaded lobed knob with a 1/2 inch thread engagement depth, including panel assemblies, jigs, fixtures, and adjustable mechanical equipment.

Installation Notes

Installation is performed by hand or with minimal tooling by machinists, assemblers, or maintenance technicians. Verify that the mating threaded insert or stud is clean and undamaged before installation. Do not exceed the hand-tightening torque appropriate for aluminum-threaded components, as over-tightening can strip the internal threads. Ensure thread engagement depth matches the 1/2 inch thread length of this knob.