Value Collection MSFI0-400500-100BX 4-40 Flat Head Slotted Machine

Product Description

The VALUE COLLECTION MSFI0-400500-100BX is a 4-40 x 0.5-inch overall length flat head machine screw designed for general fastening applications in light assemblies, enclosures, and equipment panels. Made from Grade 2 steel with a zinc finish, it delivers basic corrosion resistance suitable for indoor and protected environments. The slotted flat head sits flush with or slightly below the mating surface when installed in a countersunk hole, making it a common choice where a smooth surface profile is required. This box contains 100 screws, supporting both bench-stock replenishment and moderate production use.

These screws are suited for use in electrical enclosures, light-duty metal and plastic assemblies, HVAC control panels, and other applications calling for a standard 4-40 Unified National Coarse thread fastener. The 0.5-inch overall length equals the length under the head, indicating the full shank is threaded. They are installed by electricians, HVAC technicians, and mechanical assemblers working with small-format threaded hardware in residential and light commercial equipment.

Key Features

• 4-40 UNC thread for compatibility with standard tapped holes and hex nuts in light assemblies
• Flat head profile allows flush or countersunk installation for a clean surface finish
• Slotted drive accepts a standard flat-blade screwdriver
• Grade 2 steel construction provides adequate strength for light-duty fastening
• Zinc finish offers basic corrosion resistance for indoor and protected environments
• Box quantity of 100 pieces supports bench-stock and small production needs

Compatibility

Designed as a standard 4-40 UNC flat head slotted machine screw suitable for any application requiring a 4-40 threaded fastener with a 0.5-inch overall length and flat head profile.

Installation Notes

Install using a flat-blade screwdriver sized to the slot to avoid cam-out and head damage. When threading into metal, ensure the mating hole is tapped to 4-40 UNC specification; for flush seating, the receiving surface should be properly countersunk to match the flat head angle. De-energize any electrical equipment before fastening within live panels or enclosures per applicable NEC guidelines. Do not overtighten Grade 2 fasteners in thin materials, as the lower tensile rating makes them susceptible to stripping.