Description
Monster Overview:
Dependable, compact, and strong — Bulk #4-40 Button Head Socket Cap Screws from Monster Bolts are built to handle demanding fastening applications while maintaining a clean, low-profile appearance. These high-strength screws are made from ASTM A574 alloy steel and finished with a thermal black oxide + oil treatment for a sleek, professional look and mild corrosion resistance.
Each screw meets ASME B18.3 and IFI-111 dimensional standards, ensuring consistency and precision in every batch. All Monster Bolts black oxide socket fasteners are fully RoHS compliant and ship directly from our U.S. warehouse for fast, reliable delivery to your shop or production floor.
Key Features:
- High Strength: Alloy steel construction per ASTM A574 provides ~180,000 psi tensile and 162,000 psi yield strength for diameters ≤ 1/2".
- Button Head Design: Low, rounded head offers a clean appearance and snag-resistant profile ideal for visible or tight assemblies.
- Drive: Uses a standard 1/16" hex key for precise torque application. Available here if you need a fresh one!
- Finish: Thermal black oxide + oil coating for mild oxidation resistance and smooth handling.
- Compliance: Meets ASME B18.3 / IFI-111 standards; material conforms to ASTM A574; fully RoHS compliant.
Monster Specifications:
| Specification | Detail |
|---|---|
| Diameter / Thread Size | #4-40 (UNC – Unified Coarse Thread) |
| Drive Size | 1/16" Hex Key (Allen Wrench) |
| Material | Alloy Steel per ASTM A574 (≈ Class 12.9 Equivalent) |
| Finish | Thermal Black Oxide + Oil |
| Tensile Strength | 180,000 psi (≤ 1/2" Diameter) |
| Yield Strength | 162,000 psi (≤ 1/2" Diameter) |
| Hardness | Rockwell C39 Minimum |
| Standards | ASME B18.3 / IFI-111 / ASTM A574 |
| RoHS Compliance | Yes – Black Oxide Finish |
Measurement Note:
For button head socket cap screws, overall length is measured from under the head to the tip of the screw.
Matching Products:
- Matching Nuts: Compatible #4-40 nuts available in our Bulk U.S. Nuts Collection.
- Matching Washers: Pair with flat and lock washers from our Bulk U.S. Washers Collection.
- Hex Key: Uses a 1/16" hex key – Available here.
Order with Confidence:
Every Monster Bolts bulk order ships fast from our U.S. warehouse and is backed by our dedication to quality, consistency, and customer satisfaction. Trusted by engineers, builders, and repair professionals nationwide.