Mutual Screw & Supply

1-3/8-6 X 3-1/2" Socket Cap Screws | Hex Socket Drive | Fully Threaded | Alloy Steel Thermal Black Oxide

1-3/8-6 X 3-1/2" Socket Cap Screws | Hex Socket Drive | Fully Threaded | Alloy - Main image
$33.25 $53.63 In stock

These 13/8-6 x 3-1/2" 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: 13/8-6
  • Length: 3-1/2"
  • 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: 13/8-6
  • Length: 3-1/2"
  • Threads per inch: 6
  • Measurement type: Inch
  • Pack quantity: 1 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 (4.6 / 5 · 5 reviews)

Timothy ★★★★★

The black oxide finish on these screws matches perfectly with my other tooling components, and the hex socket drive makes them easy to tighten in tight spaces on my jig. Installed four of them on a precision assembly table today, and the threads cut clean without any binding.

Sophia ★★★★★

The black oxide finish on these screws gave them a nice, consistent look against the steel jig I’m building, and they threaded in smoothly without any binding. Exactly the heavy-duty hold I needed for a tooling fixture.

Eli A. ★★★★★

These 13/8-6 screws fit perfectly into my milling machine’s jig, and the black oxide coating really resists the shop grime. The hex socket drive made installation a breeze with no stripping.