5/16" Stainless Steel Hex Lag Screws

Grade A2 / 18-8 / 304 Stainless Steel – ASME B18.2.1 Compliant

Secure your projects with 5/16" Stainless Steel Hex Lag Screws from Monster Bolts. Made from A2 / 18-8 / 304 stainless steel, these fasteners deliver outstanding corrosion resistance and strength for heavy-duty outdoor use in decking, framing, and structural applications.

Key Specifications

• Diameter: 5/16 inch
• Thread Pitch: 9 Threads Per Inch (9 TPI)
• Wrench Size (Across Flats): 1/2 inch
• Type: Hex Lag Screw (also called Lag Bolt)
• System of Measurement: Inch / Imperial / US
• Material Grade: Stainless Steel A2 / 18-8 / 304
• Standard: ASME B18.2.1 compliant

Material Advantages

• Corrosion Resistance: Built for outdoor and marine-adjacent environments.
• Heavy-Duty Strength: Reliable holding power for structural wood connections.
• Long Service Life: Resists rust and oxidation for durable performance.
• Low Magnetism: A2 / 18-8 stainless is generally non-magnetic.

Common Applications

• Deck framing and ledger attachments
• Outdoor structures, pergolas, and fencing
• Timber framing and heavy carpentry
• General construction and contractor jobs

Installation Tips

• Pre-drill pilot holes to prevent wood splitting and ease installation.
• Use a 1/2" wrench or socket for proper torque.
• Apply anti-seize on stainless threads to help prevent galling.
• Verify required length and load for your specific application.

Order With Confidence

Choose 5/16" Stainless Steel Hex Lag Screws for dependable, heavy-duty performance in outdoor builds. Enjoy fast U.S. shipping and Monster Bolts’ responsive support.