Mutual Screw & Supply

5/16-18 X 3-1/4" Socket Cap Screws | Hex Socket Drive | Nylon Pellet | Partially Threaded | Alloy Steel Thermal Black Oxide (100 / Pkg.)

5/16-18 X 3-1/4" Socket Cap Screws | Hex Socket Drive | Nylon Pellet | - Main image
$340.72 $532.37 In stock

These 5/16-18 x 3-1/4" 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: Partially Threaded
  • Thread size: 5/16-18
  • Length: 3-1/4"
  • 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: Partially Threaded
  • Thread size: 5/16-18
  • Length: 3-1/4"
  • Threads per inch: 18
  • Measurement type: Inch
  • Pack quantity: 100 per package
Before you pay

Check the method and total at checkout.

When it ships

Allow for processing time as well as the journey to you.

Standard Shipping: Handling (business days) 0–1; Transit (business days) 7–15.

Express Shipping: Handling (business days) 0–1; Transit (business days) 7–15.

View policy
If you need a refund

Keep your order number and contact the store to start.

Please contact us for the refund processing timeframe before returning an item.

View policy
Delivery costs

Review the cost for your destination and chosen service.

Standard Shipping · United States: $0.00

Express Shipping · United States: $3.99

View policy
Returning an item

Check the return conditions before sending anything back.

United States · Return window (days after delivery): 30. Return method: By mail. Return postage: Seller pays.

View policy

Customer Reviews (4.2 / 5 · 5 reviews)

Emily C. ★★★★★

The black oxide finish is holding up great on my jig fixtures, and the partial threads make alignment a lot easier than I expected. These are solidly built for the price, and I’ve already ordered another pack.

Leo Y. ★★★★★

Installed these in a jig for a production run and the nylon pellet held tight even with frequent adjustments. The thermal black oxide finish looks clean and seems like it won't chip easily.

Joseph ★★★★☆

The nylon pellet feature made these perfect for a jig I built—they lock tight without backing out. The 100-count pack is a solid value for this size.