Mutual Screw & Supply

5/16-18 X 6-1/2" Hex Head Cap Screws | USA Made | Grade 8 Steel Yellow Zinc (250 / Pkg.)

5/16-18 X 6-1/2" Hex Head Cap Screws | USA Made | Grade 8 Steel Yellow Zinc - Main image
$397.59 $621.23 In stock

5/16-18 x 6-1/2" 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 250

Specifications

  • Thread Size: 5/16-18
  • Length: 6-1/2"
  • Threads Per Inch: 18
  • Material: Steel
  • Grade: Grade 8
  • Finish: Yellow Zinc CR+3
  • Pack Quantity: 250
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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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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 (4.8 / 5 · 5 reviews)

Edward ★★★★★

The yellow zinc finish on these looks great and held up fine during assembly, no marring or rust flakes. Each of the 250 bolts threaded cleanly into my equipment frame, and the Grade 8 rating gives me confidence they won’t snap under load. Even the packaging was sturdy enough to store the extras in

Zoe K. ★★★★★

I needed a longer bolt for a custom bracket on a heavy press, and these 6-1/2" grade 8 screws threaded in smoothly without any binding. The zinc coating looks consistent and should hold up fine in my shop.

William ★★★★★

These bolts cinched down evenly on my tractor's frame with no binding. The 6-1/2 inch length was exactly what I needed for that thick bracket assembly, and the grade 8 steel feels solid.