Mutual Screw & Supply

1/4-20 X 3-1/4" Carriage Bolts | Fully Threaded | A307 Grade A Zinc Plated Steel (150 / Pkg.)

1/4-20 X 3-1/4" Carriage Bolts | Fully Threaded | A307 Grade A Zinc Plated - Main image
$13.16 $18.03 In stock

1/4-20 X 3-1/4" 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
  • Fully Threaded
  • Sold in bulk packs

Specifications

  • Thread Size: 1/4-20
  • Length: 3-1/4"
  • Threads Per Inch: 20
  • Material: A307 Grade A Zinc Plated Steel
  • Finish: Zinc Plated
  • Thread Style: Fully Threaded
  • Pack Quantity: 50
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Standard Shipping: Handling (business days) 0–1; Transit (business days) 7–15.

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 (5.0 / 5 · 5 reviews)

Hazel Y. ★★★★★

The zinc plating on these bolts looks clean and even, and the fully threaded design made them much easier to work with than I expected. I used a dozen to secure a heavy bench to the wall, and they held firm with no slipping.

Ellie ★★★★★

The square neck grabbed the wood instantly—no spinning or cussing trying to hold the head still. Fully threaded meant I could stack washers and a lock nut without running out of threads on a 3-1/4" length. Zinc plating looks clean and hasn't shown a speck of rust after two weeks on the patio frame.

Abigail ★★★★★

These bolts fit perfectly into the pre-drilled holes on my deck boards and the threads are clean and consistent. For 150 pieces at this price, you can't beat the value when you're working on a big project.