Mutual Screw & Supply

5/16-18 X 3-3/4" Carriage Bolts | Fully Threaded | A307 Grade A Plain Steel (100 / Pkg.)

5/16-18 X 3-3/4" Carriage Bolts | Fully Threaded | A307 Grade A Plain Steel - Main image
$16.56 $22.38 In stock

5/16-18 X 3-3/4" 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
  • Fully Threaded
  • Sold in bulk packs

Specifications

  • Thread Size: 5/16-18
  • Length: 3-3/4"
  • Threads Per Inch: 18
  • Material: A307 Grade A Plain Steel
  • Finish: Plain
  • Thread Style: Fully Threaded
  • Pack Quantity: 50
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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 (4.4 / 5 · 5 reviews)

Elizabeth J. ★★★★★

Put these in to rebuild a wooden garden gate and the threads grabbed the wood perfectly—no spinning. The square neck really does bite in just like it’s supposed to.

Abigail ★★★★★

The heads sit flush and the square neck grabs the wood tight, so I didn't need a wrench to hold them still while tightening. All 100 came out of the box clean with no bent threads, worked perfectly for my deck frame repair.

George ★★★★☆

The square neck under the head grabbed the wood exactly as it should, which made driving these into a fence repair a lot less frustrating than I expected. Only gripe is the plain steel finish means I had to oil them right away, but for the price per piece, they're a solid buy.