Mutual Screw & Supply

5/16-18 X 1-1/8" Hex Head Cap Screws | USA Made | Grade 8 Steel Yellow Zinc | Fully Threaded (100 / Pkg.)

5/16-18 X 1-1/8" Hex Head Cap Screws | USA Made | Grade 8 Steel Yellow Zinc | - Main image
$31.23 $44.61 In stock

5/16-18 x 1-1/8" hex head cap screws for machinery, equipment assembly and general industrial fastening.

  • Grade 8 Steel Yellow Zinc construction
  • Fully Threaded
  • Hex head for wrench or socket drive
  • Made in the USA
  • Sold in packs of 100

Specifications

  • Thread Size: 5/16-18
  • Length: 1-1/8"
  • Threads Per Inch: 18
  • Material: Steel
  • Grade: Grade 8
  • Finish: Yellow Zinc CR+3
  • Thread Style: Fully Threaded
  • Pack Quantity: 100
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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 (4.6 / 5 · 5 reviews)

Elizabeth F. ★★★★★

Used these to reassemble a piece of heavy shop equipment, and the Grade 8 steel feels noticeably tougher than the old hardware. The hex head seated easily with a socket, and all one hundred bolts were uniform without any burs or odd threads. Definitely solid for the price.

Amelia B. ★★★★★

These fit perfectly on my trailer hitch bracket, and the grade 8 steel gives me confidence they’ll hold up under heavy loads. The threads are clean and started easily with a socket.

Claire ★★★★★

Yellow zinc coating looks even better in person, and the threads are clean enough to spin on by hand before I torqued them down. I've used cheaper Grade 5 bolts that stripped, but these Grade 8s held tight on my equipment frame.