Mutual Screw & Supply

5/16-18 X 1-3/8" Hex Head Cap Screws | USA Made | Grade 8 Steel Yellow Zinc | Partially Threaded (100 / Pkg.)

5/16-18 X 1-3/8" Hex Head Cap Screws | USA Made | Grade 8 Steel Yellow Zinc | - Main image
$35.08 $54.81 In stock

5/16-18 x 1-3/8" hex head cap screws for machinery, equipment assembly and general industrial fastening.

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

Specifications

  • Thread Size: 5/16-18
  • Length: 1-3/8"
  • Threads Per Inch: 18
  • Material: Steel
  • Grade: Grade 8
  • Finish: Yellow Zinc CR+3
  • Thread Style: Partially 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 (4.4 / 5 · 5 reviews)

Ryan ★★★★★

The partially threaded design is a lifesaver when you need a firm bite before cinching down on a heavy bracket. The yellow zinc finish looks clean and the threads engaged smoothly with my socket; these held up without any stripping during assembly.

Natalie ★★★★★

I needed a full set of Grade 8 hardware for a heavy-duty jig I’m building, and these hex head cap screws with the partially threaded design were exactly what I needed—they grip securely without bottoming out.

Richard G. ★★★★★

I needed some strong fasteners for a trailer hitch repair and these grade 8 bolts held up perfectly under the torque. The partially threaded design made installation a lot easier than dealing with fully threaded ones.