Value Collection R83924406 4-40 X 5/8 in Round Head Slotted Screw

Product Description

The VALUE COLLECTION R83924406 is a 4-40 UNC machine screw designed for precision fastening in light-duty mechanical assemblies. This round head, slotted drive screw measures 5/8 inches in length under the head and is manufactured from 18-8 stainless steel with a bright, uncoated finish. The 18-8 alloy offers reliable corrosion resistance in a wide range of indoor and moderate outdoor environments. This fastener is sold in a minimum order quantity of 100 pieces, making it suitable for production runs, maintenance stock, or batch assembly work. Machinists, electricians, and general trades professionals use this size for panel mounting, equipment housings, and small-component fastening applications.

This screw is a standard inch-series fastener and is appropriate for use in electrical enclosures, HVAC control panels, junction boxes, and light mechanical assemblies where corrosion resistance is a priority. The 4-40 thread size is one of the most common small-machine-screw sizes in the trade and is compatible with standard 4-40 tapped holes and hex nuts. The round head profile provides a low-profile bearing surface without requiring a countersunk hole. Applications are typically found in residential and commercial service environments where stainless fasteners are specified.

Key Features

• 4-40 UNC thread for compatibility with standard inch-series tapped holes and hardware
• 5/8-inch length measured under the head for accurate stack-up calculations
• Round head profile distributes clamping load without countersinking
• Slotted drive accepts standard flat-blade screwdrivers
• 18-8 stainless steel construction provides corrosion resistance in damp or humid environments
• Bright, uncoated finish — no plating to chip, flake, or contaminate sensitive assemblies

Compatibility

Designed as a standard 4-40 UNC inch-series machine screw for use with any 4-40 tapped hole, threaded insert, or mating hex nut in that thread specification.

Installation Notes

Install using a flat-blade screwdriver sized to the slotted head to prevent cam-out and head damage. Do not over-torque small-diameter machine screws, as 18-8 stainless can gall when forced against stainless mating threads — apply an appropriate anti-seize compound if threading into stainless tapped holes. Verify thread engagement depth meets design requirements before final assembly. Electricians installing these in energized panels must de-energize and lock out the equipment per applicable NFPA 70 procedures before working inside enclosures.