Mutual Screw & Supply

5/16-18 X 1-1/4" Socket Cap Screws | Hex Socket Drive | Nylon Pellet | Fully Threaded | Alloy Steel Thermal Black Oxide (100 / Pkg.)

5/16-18 X 1-1/4" Socket Cap Screws | Hex Socket Drive | Nylon Pellet | Fully - Main image
$157.33 $262.21 In stock

These 5/16-18 x 1-1/4" socket cap screws are manufactured from Alloy Steel Thermal Black Oxide, featuring a hex socket drive. They are well suited to machinery, tooling, jigs, and precision assemblies.

  • Material and finish: Alloy Steel Thermal Black Oxide
  • Drive: Hex Socket Drive
  • Thread style: Fully Threaded
  • Thread size: 5/16-18
  • Length: 1-1/4"
  • Applications: Machinery, tooling, jigs, and precision assemblies

Specifications

  • Product type: Socket Cap Screws
  • Material: Alloy Steel
  • Finish: Thermal Black Oxide
  • Drive type: Hex Socket Drive
  • Thread style: Fully Threaded
  • Thread size: 5/16-18
  • Length: 1-1/4"
  • Threads per inch: 18
  • Measurement type: Inch
  • Pack quantity: 100 per package
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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 (4.8 / 5 · 5 reviews)

Zoe C. ★★★★★

The nylon pellet is a clever touch—these screws hold their setting much better than plain ones when I’m working on jigs. The fully threaded length gives me plenty of grip for the 5/16-18 holes, and the black oxide looks sharp on my tooling.

Sebastian K. ★★★★★

The black oxide finish on these hex screws is perfect for jig building—no glare under shop lights. Thread engagement feels smooth and precise, and the 100-count pack is a solid value for tooling projects.

Chloe O. ★★★★★

The nylon pellet locking feature on these socket cap screws really impressed me—they held tight on a jig build without any loosening. The black oxide finish looks clean and seems durable for shop use.