Value Collection 221139PR Shoulder Screw 1/2 in Alloy Steel

Product Description

The VALUE COLLECTION 221139PR is a Grade 8 alloy steel shoulder screw with a 0.500 inch shoulder diameter and a 3.5 inch shoulder length. The shoulder provides a precise, hardened bearing surface used as a pivot point, axle, or locating pin in mechanical assemblies. The fastener features a hex socket drive accepting a 1/4 inch hex key and an uncoated finish. The 3/8-16 UNC threaded section clamps the screw securely into a tapped hole, while the shoulder extends above the mating surface to guide moving components. Licensed mechanics, millwrights, and maintenance technicians are the typical installers for this type of fastener.

Shoulder screws of this pattern see widespread use in jigs and fixtures, die sets, punch press tooling, conveyor linkages, and general precision mechanical assemblies where a controlled-clearance bearing surface is required. The 0.500 inch shoulder diameter and 3.5 inch shoulder length suit mid-range stroke or linkage applications. The uncoated Grade 8 alloy steel construction is appropriate for dry or lightly lubricated mechanical environments where high shear strength and dimensional precision are priorities. This fastener ships individually but carries a minimum order quantity of 10 units.

Key Features

• 0.500 inch shoulder diameter provides a precision bearing and locating surface
• 3.5 inch shoulder length suits medium-depth pivot and linkage applications
• Grade 8 alloy steel construction delivers high tensile and shear strength
• 3/8-16 UNC thread engages standard tapped holes for secure clamping
• 1/4 inch hex socket drive for precise torque application with a hex key or hex-bit driver
• Meets ANSI B18.3, ASME/ANSI B18.3, and ASTM A574 standards

Compatibility

Designed as an OEM-style replacement or direct-fit shoulder screw for mechanical assemblies requiring a 1/2 inch diameter shoulder, 3/8-16 UNC thread, and Grade 8 alloy steel construction per ANSI B18.3 and ASTM A574 specifications.

Installation Notes

Installation is performed by qualified mechanics or maintenance technicians using a 1/4 inch hex key or hex-bit driver. Ensure the receiving tapped hole is clean and free of debris before driving the fastener. Do not exceed the design clamping load for the 3/8-16 thread class. The shoulder must be free to rotate or slide within its mating bore without additional thread engagement interfering with shoulder clearance.