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.
| 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 |
Length is measured from under the head to the tip of the screw. Button heads are not included in the overall measurement.
Buy with confidence! Every order from Monster Bolts is backed by our commitment to quality, fast shipping, and customer satisfaction.