Gibraltar KN4C----S3--S21 Tapered Knob 1/4-20

Product Description

The GIBRALTAR KN4C----S3--S21 is a female insert tapered knob manufactured from black thermoplastic and designed for use with 1/4-20 threaded fasteners. The knob features a tapered head profile that provides a secure, ergonomic grip for manual adjustment and control applications. With an overall length of 2.0 inches, a head diameter of 1.38 inches, and a base diameter of 0.75 inches, this knob suits panel-mounted controls, equipment enclosures, and machinery adjustment points. The female insert accepts a 1/4-20 threaded stud or screw to a depth of 0.51 inches. Installers in industrial, HVAC, and electrical panel environments rely on this style of knob for tool-free manual operation of valves, dials, and adjustment mechanisms.

This tapered knob is suited for light-duty manual control applications across industrial equipment, HVAC control panels, electrical enclosures, and general machinery. It is intended for installations where a threaded stud protrudes from the surface and a hand-tightened knob is required for routine operator adjustments. The thermoplastic construction resists common shop chemicals and moisture, making it appropriate for both indoor mechanical rooms and control panel environments.

Key Features

• Female insert design accepts 1/4-20 threaded studs to a depth of 0.51 inches
• Tapered head profile provides a positive grip for tool-free manual adjustment
• Thermoplastic construction offers chemical and moisture resistance
• Black finish suits standard panel and equipment aesthetics
• Compact overall length of 2.0 inches fits space-constrained installations
• Head diameter of 1.38 inches and base diameter of 0.75 inches for balanced grip area

Compatibility

Designed as a replacement or new-installation female insert tapered knob for any application using a 1/4-20 threaded stud requiring manual hand-knob adjustment.

Installation Notes

This knob is typically installed by a maintenance technician or equipment assembler without special tools — hand-threading onto the exposed 1/4-20 stud is the standard method. Confirm the stud protrusion does not exceed the 0.51-inch hole depth before installation. Power down or de-energize any associated equipment before servicing control panels or adjustment mechanisms. Do not overtighten; thermoplastic inserts can crack under excessive torque.