Gibraltar HKS-3717A-G Steel Thumb Screw 3/8-16 Lobed

Product Description

The GIBRALTAR HKS-3717A-G is a lobed-head thumb screw machined from C-12L14 steel with a black oxide finish. It features a 3/8-16 UNC thread and measures 2-5/8 inches in overall length. The lobed aluminum head is 2 inches in diameter and 1 inch in height, providing enough grip surface for hand-tightening without tools. The flat tip and shouldered shank make it suited for panel attachment, jig fixturing, and machine guarding applications where frequent removal and reinstallation are required. Machinists, millwrights, and industrial maintenance technicians are the primary installers.

This thumb screw is used in light industrial and manufacturing environments where tool-free fastening is required. Typical applications include machine enclosure panels, fixture plates, adjustable guards, and equipment access covers. The shouldered design provides positive seating against mating surfaces, reducing the risk of over-insertion. The black oxide finish offers mild corrosion resistance in dry indoor conditions.

Key Features

• 3/8-16 UNC thread for compatibility with standard inch-series tapped holes
• Lobed aluminum head, 2 inches in diameter, allows hand-tightening without a driver
• With-shoulder design provides positive seating against panel or fixture surfaces
• C-12L14 steel body with black oxide finish for mild corrosion resistance
• Flat tip prevents marring of internal components or mating surfaces
• Overall length of 2-5/8 inches suits moderate panel thickness applications

Compatibility

Designed as a standard replacement or original-install thumb screw for 3/8-16 UNC tapped holes in industrial fixtures, machine enclosures, and equipment panels requiring tool-free fastening access.

Installation Notes

Installation is performed by hand in most applications; do not use a wrench or driver on the lobed head as this may damage the aluminum head or over-torque the fastener. Verify that the mating tapped hole conforms to 3/8-16 UNC thread standards before installation. Ensure panels or components are de-energized and equipment is locked out before servicing any access covers secured by this fastener. Black oxide finish is not rated for wet or high-humidity environments without additional corrosion protection.