Mutual Screw & Supply

5/16-18 X 12" Carriage Bolts | A307 Grade A Zinc Plated Steel (25 / Pkg.)

5/16-18 X 12" Carriage Bolts | A307 Grade A Zinc Plated Steel (25 / Pkg.) - Main image
$12.17 $19.95 In stock

5/16-18 X 12" Carriage Bolts in A307 Grade A Zinc Plated 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 Zinc Plated Steel construction
  • Coarse thread for use in wood and with nuts and washers
  • Sold in bulk packs

Specifications

  • Thread Size: 5/16-18
  • Length: 12"
  • Threads Per Inch: 18
  • Material: A307 Grade A Zinc Plated Steel
  • Finish: Zinc Plated
  • Pack Quantity: 25
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Express Shipping: Handling (business days) 0–1; Transit (business days) 7–15.

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Standard Shipping · United States: $0.00

Express Shipping · United States: $3.99

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

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Customer Reviews (4.6 / 5 · 5 reviews)

Evelyn ★★★★★

The full 12-inch length is exactly what I needed for a thick timber frame project, and the square neck under the head dug right into the wood—no spinning or fussing once the wrench was on. The zinc plating looks clean and hasn’t shown a single speck of rust after a week of rain on the deck.

Aurora S. ★★★★★

The square neck under the head locked perfectly into my wooden posts, so the bolt didn’t spin at all while I tightened the nut. These 12-inch lengths were just right for my deck repair, and the zinc coating looks clean without being flashy.

Chloe L. ★★★★★

I needed some long carriage bolts for a heavy wooden gate repair, and these 12-inchers went through the beam nicely without spinning. The zinc plating feels durable enough to resist the weather, too.