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The Miller 108940 is a specialized machine screw engineered for structural and panel fastening within Miller welding power sources and wire feeders. Understanding the specifications of this fastener is essential for technicians and maintenance personnel to ensure proper reassembly of equipment.
This screw utilizes a standard 1/4-20 UNC (Unified National Coarse) thread pitch. The major diameter is 0.250 inches with 20 threads per inch, a common standard for industrial machinery that balances clamping force with ease of assembly. The length of the screw is 0.75 inches (3/4"), measured from under the head to the tip of the fastener. It is crucial to verify this length before installation to ensure full thread engagement without bottoming out in blind holes or interfering with internal components.
The fastener features a Hex Washer Head (HexwHD). This design incorporates a flange that acts as a permanently attached washer. The washer diameter is specified as 0.61 inches, providing a broad bearing surface. This distributes the torque load over a wider area, which is critical for securing sheet metal chassis parts or components with slotted holes. The head is driven via a standard hex socket (typically 3/8" or 7/16").
Material strength is rated at Grade 5. Grade 5 fasteners are made from medium carbon steel that has been quenched and tempered. They are identified by three radial lines on the head. With a minimum proof load of 85,000 psi and a minimum tensile strength of 120,000 psi, this screw offers robust resistance to shearing and stretching forces. The plated finish (likely Zinc) provides sacrificial corrosion protection, essential for maintaining thread integrity in shop environments where moisture and fumes are present.
Summary of Specs:
| Additional Information |
|---|
| Brand:Miller |
| Packaging Description:1-per-ea |
| Thread Size:1/4-20 UNC |
| Length:0.75 in |
| Head Type:Hex Washer Head |
| Grade:Grade 5 |
| Washer Diameter:0.61 inch |
| Finish:Plated |
$350 Rebate
$350 Rebate
