Holo-krome 08040 Shoulder Screw 3/8 in Alloy Steel Hex Socket

Product Description

The HOLO-KROME 08040 is a Grade 8 alloy steel shoulder screw designed for precision mechanical assemblies where a hardened, close-tolerance shoulder is required as a bearing, pivot, or guide surface. The screw features a 3/8-inch shoulder diameter and a 3/4-inch shoulder length, with a 5/16-18 UNRC threaded end measuring 1/2 inch in length. Drive is a 3/16-inch hex socket. Overall length is 1.5 inches. The uncoated finish makes it suitable for applications where post-treatment or close dimensional fit is critical. Mechanical assemblers, maintenance technicians, and industrial equipment builders are the typical installers.

This shoulder screw is used in jigs, fixtures, dies, and general precision mechanical assemblies where a hardened shoulder acts as a pivot point, linear guide, or bearing journal. It is appropriate for both light industrial and heavy-duty machine tool applications. The Grade 8 alloy steel construction and compliance with ASME B18.3 and ASME B1.1 standards make it a reliable choice for demanding mechanical environments where dimensional consistency is essential.

Key Features

• 3/8-inch shoulder diameter with close-tolerance head diameter range of 0.543 to 0.562 inches
• Grade 8 alloy steel construction for high tensile strength and wear resistance
• 3/16-inch hex socket drive for precise torque application in confined spaces
• 5/16-18 UNRC thread form compliant with ASME B1.1
• Uncoated finish maintains tight dimensional tolerances for press-fit or slip-fit shoulder applications
• Meets ASME B18.3 standards for socket head cap and shoulder screws

Compatibility

Designed as a standard ASME B18.3 shoulder screw for use in precision mechanical assemblies, jigs, fixtures, and die sets requiring a 3/8-inch diameter shoulder with a 5/16-18 threaded shank.

Installation Notes

Installation should be performed by a qualified mechanical assembler or machinist using an appropriately sized 3/16-inch hex key or socket driver. Ensure the mating bore is sized to the correct tolerance class for the intended shoulder fit before installation. Do not over-torque the threaded end, as this can damage the thread or distort the shoulder fitment. Verify compliance with applicable machinery or equipment standards before use in safety-critical assemblies.