Mutual Screw & Supply

5/16-24 X 1-1/4" Socket Cap Screws | Flat Head Hex Socket Drive | Nylon Pellet | Fully Threaded | Alloy Steel Thermal Black Oxide (100 / Pkg.)

5/16-24 X 1-1/4" Socket Cap Screws | Flat Head Hex Socket Drive | Nylon Pellet - Main image
$277.87 $396.95 In stock

These 5/16-24 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
  • Head style: Flat Head
  • Drive: Hex Socket Drive
  • Thread style: Fully Threaded
  • Thread size: 5/16-24
  • Length: 1-1/4"
  • Applications: Machinery, tooling, jigs, and precision assemblies

Specifications

  • Product type: Socket Cap Screws
  • Head style: Flat Head
  • Material: Alloy Steel
  • Finish: Thermal Black Oxide
  • Drive type: Hex Socket Drive
  • Thread style: Fully Threaded
  • Thread size: 5/16-24
  • Length: 1-1/4"
  • Threads per inch: 24
  • 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 (4.4 / 5 · 5 reviews)

Scarlett R. ★★★★★

The nylon pellet lock is the standout here—screws stay put even after a day of vibration on my jig setup. Threads cut clean into the holes, and the black oxide held up without any rust after wiping them down.

Timothy ★★★★★

I’m rebuilding a jig and the nylon pellet in these is a nice touch—it keeps the screw from vibrating loose even on a machine that shakes constantly. The flat head sits flush and the black oxide let them slide right into place without any galling on the first try.

Adam ★★★★☆

I needed some clean-looking fasteners for a jig build, and these socket cap screws fit the bill perfectly. The black oxide finish is uniform and hasn't shown any wear after a few test assemblies. My only minor gripe is that the hex drive felt a tad tight in one or two of them, but it's nothing a sta