Description
Product Overview
Choose dependable strength with Bulk 5/16"-18 Grade 8 Hex Cap Screws in a durable zinc yellow CR+3 finish, Made in USA for consistent quality and performance. These high-strength UNC bolts are ideal for automotive work, machinery repair, construction, fabrication, and industrial maintenance where dependable clamp load and reliability are essential.
Manufactured from premium alloy steel to SAE J429 Grade 8 standards and plated with chromate-converted zinc (CR+3), these screws offer excellent corrosion resistance along with the bright, easily identifiable yellow appearance commonly used on high-grade hardware. CR+3 plating is RoHS compliant, meeting modern regulatory and environmental requirements.
These Made in USA fasteners are part of our Monster Bolts USA Fasteners Collection and ship quickly from Florida with reliable, traceable quality.
Key Features
- Size: 5/16"-18 UNC (coarse thread).
- Material Strength: High-strength Grade 8 alloy steel.
- Finish: Zinc Yellow CR+3 for corrosion resistance and high visibility.
- Compliance: CR+3 zinc plating is RoHS compliant.
- Origin: Made in USA for consistency and traceability.
- Uses: Automotive, machinery, construction, fixtures, tooling, and industrial equipment.
- Bulk Packaging: Monster Bolts bulk quantities offer the lowest cost per piece for individuals and businesses needing larger volumes.
Monster Specifications
| Specification | Details |
|---|---|
| Diameter | 5/16" (0.3125") |
| Thread Size | 5/16"-18 UNC (coarse thread) |
| Head Style | Hex cap screw / hex bolt |
| Wrench Size | 1/2" hex wrench/socket |
| Material | Alloy steel, Grade 8 |
| Finish / Plating | Zinc yellow CR+3 (chromate-converted zinc), RoHS compliant |
| Country of Origin | Made in USA |
| Standards | ASME B18.2.1 dimensions, SAE J429 Grade 8 mechanical properties |
| System of Measurement | Inch / SAE |
| Lengths Available | Offered in multiple lengths; select your required size above. |
| Packaging | Monster Bolts bulk quantities offer the lowest cost per piece for individuals and businesses needing larger volumes. |
Matching Nuts & Washers
Pair these 5/16-18 bolts with Made in USA nuts and washers from the same collection:
- 5/16-18 Hex Nuts: Available in USA-made zinc yellow and plain steel options within the USA Fasteners collection.
- Flat & Lock Washers: Choose USA-made washers for proper load distribution and vibration resistance.
- For marine and rigging hardware, visit our USA-machined cable & rigging components.
Why Choose Monster Bolts?
- Made in USA: Reliable, traceable quality for critical applications.
- Bulk value: Monster Bolts bulk quantities reduce cost per piece for shops and production crews.
- Fast fulfillment: Ships quickly from our Florida warehouse.
- Real support: Fastener specialists ready to assist.
Order Yours Today
Stock up with Made in USA 5/16-18 Grade 8 hex cap screws in zinc yellow CR+3 finish. Select length and quantity above and click "Add to Cart" to get reliable, high-strength hardware at the best bulk value.