Gibraltar HKS-3117A-G Steel Thumb Screw 5/16-18 Lobed Head

Product Description

The GIBRALTAR HKS-3117A-G is a lobed-head thumb screw designed for tool-free fastening in mechanical assemblies, enclosures, and equipment panels. The fastener features a large 2-inch diameter aluminum lobed head that provides a positive finger grip without requiring a driver, paired with a C12L14 steel threaded shank finished in black oxide for corrosion resistance. At 2-5/8 inches overall length with a 1-inch head height and a flat tip, this screw suits applications where frequent removal and reinstallation are required. The shoulder design locates the fastener consistently in the mating component. Millwrights, equipment technicians, and panel builders install this type of hardware during assembly or field service.

This thumb screw is used in industrial and commercial equipment assemblies where hand-tightened fasteners replace conventional hex or slotted hardware. Typical applications include access panel retention, enclosure covers, junction box lids, and machine guard attachment. The 5/16-18 UNC thread is one of the most common inch-series coarse-thread sizes, making this fastener compatible with a wide range of standard tapped holes in steel, aluminum, and plastic components. The black oxide finish blends with dark-finished enclosures and provides light surface protection in dry indoor environments.

Key Features

• Lobed head allows tool-free installation and removal by hand
• 2-inch head diameter provides generous grip surface for finger tightening
• C12L14 steel shank offers good machinability and consistent thread quality
• Black oxide finish provides mild corrosion resistance in dry indoor environments
• With-shoulder design for consistent positioning in the mating part
• Flat tip for standard through-hole and tapped-hole applications

Compatibility

Designed for use in standard 5/16-18 UNC tapped holes in steel, aluminum, or plastic panels and enclosures where hand-operated fastening is required.

Installation Notes

Installation does not require tools under normal hand-tightening conditions. Ensure the mating tapped hole is clean and free of debris before threading the fastener. Do not use a driver or wrench to force the lobed head beyond finger-tight, as this may strip the aluminum head or damage the mating threads. Follow applicable equipment manufacturer guidelines for torque requirements if mechanical tightening is specified.