Gibraltar KN4C-B4-21-G Ball Knob 1-1/2 in Female Insert

Product Description

The GIBRALTAR KN4C-B4-21-G is a thermoplastic ball knob with a female insert mount, designed for use on machine controls, adjustable fixtures, and industrial equipment where a secure, hand-operated grip is needed. The knob measures 1-1/2 inches in diameter and stands 1-13/32 inches tall, with a smooth grip surface and a black finish. The female insert accepts a 1/4-20 threaded fastener with a hole depth of 5/8 inches. This style of control knob is installed by machinists, equipment technicians, and maintenance professionals on a wide range of light industrial and commercial applications.

This ball knob suits residential and commercial equipment panels, jigs, fixtures, clamps, and adjustable mechanical assemblies that require frequent manual positioning. The female insert design allows it to thread directly onto a 1/4-20 stud or bolt without additional hardware. It is a standard replacement or upgrade knob for control panels, machine tool setups, and equipment enclosures requiring a reliable hand grip.

Key Features

• Female insert mount accepts 1/4-20 threaded fasteners directly
• 1-1/2 inch diameter ball profile for comfortable hand grip
• Thermoplastic construction offers durability and chemical resistance in light industrial use
• Smooth grip surface suits applications requiring clean, snag-free operation
• 5/8 inch hole depth provides adequate thread engagement for secure fastening
• Black color finish for a standard, professional appearance on control panels

Compatibility

Designed as an OEM-style replacement or standard-fit control knob for equipment and fixtures using 1/4-20 threaded studs or bolts requiring a 1-1/2 inch diameter ball knob with female insert mount.

Installation Notes

Installation requires no special tools — thread the knob directly onto a 1/4-20 stud by hand until snug. Verify that the stud length does not exceed the 5/8 inch hole depth to avoid bottoming out before full seating. No power shutoff is required for most panel and fixture installations, but always follow applicable equipment lockout procedures when working on energized machinery.