Value Collection 201018PR Button Socket Cap Screw 4-40

Product Description

The VALUE COLLECTION 201018PR is a button socket cap screw designed for applications where a low-profile head is required and clearance is limited. It features a 4-40 UNC thread and a 3/8-inch length under the head, with a 1/16-inch hex socket drive. Manufactured from alloy steel with a black oxide finish, the fastener meets ANSI/ASME B18.3 and ASTM F835 standards. Hardness is rated at 36-43 HRC, providing solid shear and tensile resistance in precision assemblies. The fully threaded shank and Class 3A thread fit deliver tight tolerances and reliable engagement. This screw is installed by machinists, assemblers, and mechanical technicians working on instrumentation, electronics, and light mechanical assemblies.

This screw is well-suited for low-profile fastening in tight spaces where a standard hex socket cap screw head would interfere with adjacent components. Common applications include instrument panels, electronics enclosures, jigs, fixtures, and precision mechanical assemblies. The right-hand UNC thread is the standard in most inch-measurement applications across industrial and commercial environments. The black oxide coating provides mild corrosion resistance and reduces light reflection, which is important in optical and electronic assemblies.

Key Features

• Button head profile reduces overall stack height in space-constrained assemblies
• 1/16-inch hex socket drive for precise torque application with standard hex keys
• Alloy steel construction with 36-43 HRC hardness for strength in small-fastener applications
• Black oxide coating provides mild corrosion resistance and a low-reflectance finish
• Fully threaded shank with Class 3A thread fit for consistent engagement
• Meets ANSI/ASME B18.3 and ASTM F835 dimensional and mechanical standards

Compatibility

Designed as an OEM-style and general-purpose replacement fastener for 4-40 UNC threaded applications requiring a button head profile in alloy steel construction.

Installation Notes

Installation is performed with a 1/16-inch hex key or ball-end driver. Always ensure the receiving thread is clean and free of debris before installation. Do not use an impact driver on small-diameter precision fasteners, as this can strip the socket drive or damage the thread. Verify mating thread condition and class before torquing to ensure full engagement.