Mutual Screw & Supply

5/16-18 X 8" Carriage Bolts | A307 Grade A Plain Steel (50 / Pkg.)

5/16-18 X 8" Carriage Bolts | A307 Grade A Plain Steel (50 / Pkg.) - Main image
$14.73 $23.76 In stock

5/16-18 X 8" Carriage Bolts in A307 Grade A Plain Steel. Carriage bolts feature a smooth, rounded head with a square neck underneath that pulls into the material to prevent the bolt from turning during installation, making them ideal for wood-to-wood and wood-to-metal connections.

  • Domed head with square anti-rotation neck
  • A307 Grade A Plain Steel construction
  • Coarse thread for use in wood and with nuts and washers
  • Sold in bulk packs

Specifications

  • Thread Size: 5/16-18
  • Length: 8"
  • Threads Per Inch: 18
  • Material: A307 Grade A Plain Steel
  • Finish: Plain
  • Pack Quantity: 25
Before you pay

Check the method and total at checkout.

When it ships

Allow for processing time as well as the journey to you.

Standard Shipping: Handling (business days) 0–1; Transit (business days) 7–15.

Express Shipping: Handling (business days) 0–1; Transit (business days) 7–15.

View policy
If you need a refund

Keep your order number and contact the store to start.

Please contact us for the refund processing timeframe before returning an item.

View policy
Delivery costs

Review the cost for your destination and chosen service.

Standard Shipping · United States: $0.00

Express Shipping · United States: $3.99

View policy
Returning an item

Check the return conditions before sending anything back.

United States · Return window (days after delivery): 30. Return method: By mail. Return postage: Seller pays.

View policy

Customer Reviews (4.8 / 5 · 5 reviews)

Kevin ★★★★★

I was pleasantly surprised by how smoothly the square neck seated into the wood, keeping these bolts from spinning while I tightened them. Each one measures a full 8 inches, which gave me plenty of length for a sturdy connection. Definitely worth the price for a bulk pack.

Thomas ★★★★★

These bolts were perfect for building a heavy-duty swing set, and the 8-inch length gave me plenty of bite into the pressure-treated beams. The smooth, rounded heads look much cleaner than standard hex bolts.

Christopher ★★★★★

The square neck under the head grabbed the wood really well as I tightened them, and the plain steel finish is exactly what I needed for my indoor project. These 8-inch bolts have plenty of length for thick assemblies, and the pack of 50 should last me through several builds.