Description
Monster Overview:
Fix your project right the first time with Bulk 5/16-18 Button Head Socket Cap Screws from Monster Bolts. These heavy-duty fasteners are manufactured from ASTM A574 Alloy Steel and finished with a thermal black oxide + oil coating for mild corrosion protection and a clean, professional look. Their coarse-thread (UNC) design ensures easy assembly and strong holding power in machinery, automotive, and industrial applications.
Every Monster Bolts black oxide fastener is RoHS compliant and meets or exceeds industry strength standards for 12.9 metric equivalent performance.
Monster Features:
- Material: High-strength alloy steel per ASTM A574 (12.9 metric equivalent).
- Finish: Thermal black oxide + oil for a durable, matte-black appearance and mild corrosion resistance.
- Thread: 5/16"-18 UNC – Coarse Thread (Unified National Coarse).
- Drive: 3/16" Hex Key (Allen) Drive – Available here if you need a fresh one!
- Head Type: Button Head for smooth, low-profile fastening ideal for finished surfaces.
- Compliance: All black oxide Monster Bolts fasteners are RoHS compliant.
Monster Specifications:
| Attribute | Specification |
|---|---|
| Diameter | 5/16" |
| Thread Size | 5/16"-18 UNC (Coarse Thread) |
| Drive Size | 3/16" Hex Key |
| Head Style | Button Head Socket Cap Screw |
| Material | Alloy Steel – ASTM A574 (12.9 Equivalent) |
| Finish | Thermal Black Oxide + Oil |
| Tensile Strength | 180,000 psi (≤ 1/2"), 170,000 psi (> 1/2") |
| Hardness | Rockwell C39 minimum |
| Standards | ASME B18.3 / IFI-111 |
Measurement Note:
Length is measured from under the head to the tip of the screw. Button heads are not included in the overall measurement.
Matching Products:
- Matching Nuts: Bulk U.S. Inch Nuts
- Matching Washers: Bulk U.S. Inch Washers
- Hex Keys: 3/16" Allen Key – Available here
Order Yours Today:
Buy with confidence! Every order from Monster Bolts is backed by our commitment to quality, fast shipping, and customer satisfaction.