Mutual Screw & Supply

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

5/16-18 X 3-3/4" Socket Cap Screws | Flat Head Hex Socket Drive | Partially - Main image
$127.52 $202.42 In stock

These 5/16-18 x 3-3/4" 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: Partially Threaded
  • Thread size: 5/16-18
  • Length: 3-3/4"
  • 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: Partially Threaded
  • Thread size: 5/16-18
  • Length: 3-3/4"
  • 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 (4.8 / 5 · 5 reviews)

Kevin ★★★★★

I needed partially threaded bolts for a jig I’m building, and these fit the bill perfectly. The thermal black oxide finish looks durable and hasn’t shown any chips after driving a few in.

Andrew ★★★★★

The hex socket drive grabbed perfectly with my Allen wrench, no stripping even under decent torque. The black oxide finish wiped clean easily after a day on the jig, and all 100 threads were consistent out of the bag.

Sophia Y. ★★★★★

Used a few of these for a custom jig build and the hex socket drive held up well against the torque. The black oxide coating looks clean and seems durable for the shop environment.