SKU: 33821358236

Hillman 5/16 in. Diameter x 3-1/2 in. Length Heat-Treated Steel Hex Head Cap Screw, 50-Pack

Sale price$43.19 Regular price$47.99
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Description

Hillman 5/16 in. Diameter x 3-1/2 in. Length Heat-Treated Steel Hex Head Cap Screw, 50-PackHillman Grade 8 Hex Head Cap Screws, 5 16 in. x 3 1 2 in., 50 Pack Heavy duty Grade 8 hex head cap screws engineered from heat treated steel for high strength fastening. Ideal for machinery, automotive, and structural applications where a durable, partially threaded bolt is required. Key Features: Grade 8 Strength: Heat treated steel provides superior tensile strength for demanding applications Washer Face Head: Built in washer face under head helps

Hillman Grade 8 Hex Head Cap Screws, 5/16 in. x 3-1/2 in., 50-Pack

Heavy-duty Grade 8 hex head cap screws engineered from heat-treated steel for high-strength fastening. Ideal for machinery, automotive, and structural applications where a durable, partially threaded bolt is required.


Key Features:

  • Grade 8 Strength: Heat-treated steel provides superior tensile strength for demanding applications
  • Washer Face Head: Built-in washer face under head helps improve load distribution and sealing
  • Partially Threaded Shank: Offers better shear strength and alignment in assemblies
  • Coarse Thread: USS coarse thread for quick starts and strong hold in tapped holes or with nuts
  • Bulk 50-Pack: Convenient boxed quantity for shop, jobsite, or maintenance stock

Specifications Table:

Specification Details
Diameter 5/16 inch
Length 3-1/2 inch
Material Steel
Grade Grade 8
Finish Heat-treated yellow dichromate-style
Thread Type Coarse (USS)
Head Type Hex head with washer face
Threading Partially threaded shank
Number in Package 50 pack
Packaging Type Boxed
Unit of Measure Listed by Source Metric (listing label)

Frequently Asked Questions (FAQ):

Q: Are these fully or partially threaded?
A: They are partially threaded along the shank for added shear strength.


Q: What finish do these have?
A: They feature a heat-treated yellow dichromate-style finish for extra wear resistance.


Q: What thread type are they?
A: USS coarse thread.


Q: What tools are needed for installation?
A: Tighten with a wrench or compatible socket; a drill/driver with socket adapter may also be used.


Q: What size are these bolts?
A: 5/16-inch diameter by 3-1/2-inch length.


Industrial Strength With a Sleek, Purposeful Edge

These hex cap screws bring a crisp, engineered precision to any utilitarian vignette—think open-shelf workshops and garage studios. The faceted head and clean shank create a subtle rhythm that feels both rugged and refined. Style them with exposed hardware on custom shelving or welded frames to celebrate honest materials. Their performance pedigree makes them a quiet luxury in hardworking spaces.


Upgrade your hardware bin with Grade 8 strength—add this 50-pack to your cart for reliable, long-lasting fastening.

Shipping Notes
  • Free Standard Shipping on $100+ Orders to the USA.
  • Except Preorder products are shipped in 48 hours.
  • Delivery to the USA:
  1. Standard Shipping : 3-10 business days
  • If time is of the essence, please consider selecting expedited delivery for faster service.
Exchange/Return Notes
  • We offer a 30-day return/exchange service after receiving.
  • Final sale items are not eligible for returns or exchanges.
  • To process your return/exchange, please contact us at [email protected]
  • Please click here for more details>>> Return & Exchange Policy
SKU: 33821358236

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4.4 ★★★★★
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Kevin Sanguansukdikosol
Massapequa, US
★★★★★ 5
Brightness and quality
Color: 4*2.5in Cube LED Pod
Got this for my 2024 Crosstrek. Got this one specifically due to its functionality that I wanted, quality for the price and it looks great especially DRL. I leave the Amber cover on most of the time. If you want the DRL to be on while the car is on, you can do that but it has to be rewired which I did. Love the brightness. I’ve been having this on my Crosstrek for a few months now and have no issues.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on March 3, 2026
T
Verified Purchase
Thomas Chapman
Louisville, US
★★★★★ 5
Bright lights
Color: 4*2.5in Cube LED Pod
Installed these on my Bronco as ditch lights. Very bright light and I like that you can have them be white or put the cover on them for and amber light look. Took about 30 minutes to install and wire to the upfitter switches. They shoot a wide angle covering your blind spots on dark roads. I got these to replace a three inch ditch light. They're made from heavy duty metal and stand up to the extreme weather. I like them so much that I purchased the seven inch lights and install them on the front bumper. For what they cost it was a price that I couldn't pass up. I highly recommend these lights.
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Reviewed in the United States on January 17, 2026
A
Verified Purchase
Abraham Hazim
Alexandria, US
★★★★★ 5
Great product
Color: 4*2.5in Cube LED Pod, Color: 4*2.5in Cube LED Pod
Great lighting and beautiful design!!!!!
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Reviewed in the United States on April 18, 2026
A
Verified Purchase
Amazon Customer
New York, US
★★★★★ 5
Great lights
Color: 52Inch Lights +LED Pods+ Wiring Harness, Color: 52Inch Lights +LED Pods+ Wiring Harness
These lights are awesome. Ridiculously bright and cheap. I have nothing to compare them to but they're for being so inexpensive they are tremendously bright for being a first time installer. I cannot speak to their longevity and the moisture as I only put them on a week ago and went on trail. The whistling is definitely kind of a pain. I've tried the double sided tape people mention and it softened the whistle but when you get up to 70 mph it is obnoxiously loud I'll have to tweak it some more. If you're sensitive to loud squeezing sounds it definitely makes the ride a bit uncomfortable and I would look at other light installations instead of the 52 inch bar. If you can get past the squeeling noise or dampen the sound better than I did then you can't beat the functionality for the price
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Reviewed in the United States on August 4, 2025
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Verified Purchase
Douglas hartman
Chelsea, US
★★★★★ 5
Brighter then I expected
Color: 52Inch Lights +LED Pods+ Wiring Harness
Should have went with a curved but fit under front bumper of f150 and is brighter then I ever imagined
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Reviewed in the United States on April 29, 2026

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