Gibraltar KN4C-B3-21-G Ball Knob 1-3/8 in Female Insert

Product Description

The GIBRALTAR KN4C-B3-21-G is a smooth-grip ball knob designed for manual adjustment and control applications in industrial, mechanical, and trade settings. It features a female insert mount type with a 1/4-20 threaded hole, accepting standard machine screws for secure fastening to panels, fixtures, and equipment. The knob body is molded from thermoplastic in a matte black finish, measuring 1-3/8 inches in diameter and 1-9/32 inches in height with a hole depth of 5/8 inches. Licensed tradespeople and maintenance technicians install this type of hardware as replacement or original equipment on control panels, enclosures, and adjustment mechanisms.

This ball knob is suited for light industrial and commercial environments where a low-profile, finger-grip control point is needed. Typical applications include equipment access panels, valve handles, machine guards, and enclosure latches. The smooth grip surface and thermoplastic construction make it appropriate for indoor settings where chemical resistance and moderate mechanical load are factors. It is a direct-fit hardware component for any 1/4-20 threaded stud or shaft installation.

Key Features

• Female insert mount with 1/4-20 thread for compatibility with standard machine hardware
• 1-3/8 inch diameter ball knob profile for comfortable finger grip
• 5/8 inch hole depth provides secure thread engagement on stud or bolt
• Thermoplastic construction offers durability and resistance to light chemical exposure
• Smooth grip surface suitable for frequent manual adjustment
• Black finish blends with standard industrial panel and enclosure aesthetics

Compatibility

Designed as a standard replacement or OEM-style ball knob for equipment using 1/4-20 threaded studs or bolts requiring a female insert mount style.

Installation Notes

Installation requires threading the knob onto a 1/4-20 stud or bolt to the full hole depth of 5/8 inches for proper engagement. Ensure the equipment or panel is de-energized or depressurized before replacing hardware on active control assemblies. Hand-tightening is typical for this style of knob; avoid over-torquing the thermoplastic insert. No special tools or certifications are required for standard hardware replacement.