Mutual Screw & Supply

1/4-20 X 3-1/2" Carriage Bolts | Fully Threaded | A307 Grade A Plain Steel (625 / Pkg.)

1/4-20 X 3-1/2" Carriage Bolts | Fully Threaded | A307 Grade A Plain Steel (625 - Main image
$48.16 $72.97 In stock

1/4-20 X 3-1/2" 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: 1/4-20
  • Length: 3-1/2"
  • Threads Per Inch: 20
  • Material: A307 Grade A Plain Steel
  • Finish: Plain
  • Thread Style: Fully Threaded
  • Pack Quantity: 625
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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)

Amelia P. ★★★★★

The square neck under that smooth head locked into the wood perfectly, so I didn't need a wrench to hold them still while tightening. At 3-1/2 inches fully threaded, they grabbed deep into the beam and haven't budged since.

Isabella ★★★★★

The square neck on these bolts grabbed the wood perfectly, so I didn't need a second wrench to keep them from spinning while tightening. I used about half the box on a deck repair, and every one threaded smoothly without any binding.

Thomas ★★★★★

Picked up a 625-pack of these 1/4-20 carriage bolts for a deck rebuild, and the fully threaded length made driving them into the wood much easier than partial-thread alternatives. The A307 Grade A steel feels sturdy and cost-effective for outdoor projects.