Mutual Screw & Supply

5/16-18 X 8" Hex Head Cap Screws | USA Made | Grade 8 Steel Yellow Zinc (225 / Pkg.)

5/16-18 X 8" Hex Head Cap Screws | USA Made | Grade 8 Steel Yellow Zinc (225 / - Main image
$477.43 $645.17 In stock

5/16-18 x 8" hex head cap screws for machinery, equipment assembly and general industrial fastening.

  • Grade 8 Steel Yellow Zinc construction
  • Hex head for wrench or socket drive
  • Made in the USA
  • Sold in packs of 225

Specifications

  • Thread Size: 5/16-18
  • Length: 8"
  • Threads Per Inch: 18
  • Material: Steel
  • Grade: Grade 8
  • Finish: Yellow Zinc CR+3
  • Pack Quantity: 225
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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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Delivery costs

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Standard Shipping · United States: $0.00

Express Shipping · United States: $3.99

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Returning an item

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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)

Eva ★★★★★

Had to snug up a heavy bracket on a press at the shop, and the full thread depth on these Grade 8 bolts let me get a solid bite without any slip. The zinc coating looks clean and uniform across all 225 pieces, which is nice for keeping rust off long-term.

David ★★★★★

These bolts threaded smooth and clean into my equipment frame with no binding or grit. The yellow zinc coating looks consistent across all 225 pieces, and you can feel the quality of the USA-made steel. Exactly what I needed for heavy-duty assembly work.

Natalie F. ★★★★★

I needed some heavy-duty 8-inch bolts for a piece of farm equipment, and these cap screws threaded in perfectly without any binding. The hex head made it easy to torque them down with a socket wrench, and the yellow zinc finish looks like it will hold up outdoors.