Mutual Screw & Supply

HOLO-KROME 86646 5/16-18 X 4" Socket Cap Screws | Hex Socket Drive | Alloy Steel Thermal Black Oxide (50 / Pkg.)

HOLO-KROME 86646 5/16-18 X 4" Socket Cap Screws | Hex Socket Drive | Alloy - Main image
$24.44 $40.74 In stock

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

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

Specifications

  • Product type: Socket Cap Screws
  • Material: Alloy Steel
  • Finish: Thermal Black Oxide
  • Drive type: Socket Drive
  • Thread size: 5/16-18
  • Length: 4"
  • Threads per inch: 18
  • Measurement type: Inch
  • Pack quantity: 50 per package
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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)

Sebastian X. ★★★★★

The black oxide finish on these screws gives them a nice, uniform look, and the hex socket drive grabbed my Allen key perfectly without any stripping. I used about thirty of them on a steel jig and the threads cut cleanly all the way in. Solid fasteners for the price.

Grace ★★★★★

Threaded all fifty into a fixture plate this afternoon without a single stripped drive—the black oxide coating lets them seat smoothly and the 4" length gave plenty of grip for the base plate. They feel solid under a torque wrench, no wobble or flex.

Ryan ★★★★★

Bought these for a jig I'm building, and the 5/16-18 threads seated cleanly every time — no binding or galling even on the third or fourth re-tighten. At 4 inches long, they've got plenty of reach for thicker stack-ups, and the thermal black oxide looks like it'll shrug off shop grime.