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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Janet Lanier
Lexington, US
★★★★★ 4
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A bit wobbly, but good enough for the price when you need a solid background for remote work calls.
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Reviewed in the United States on May 6, 2026
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Lateefah
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★★★★★ 5
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Color: Black, Size: Standard - 4 Panel
I absolutely love this 4-panel room divider! It was super easy to assemble — I had it set up in just a few minutes. The material isn’t too see-through, which gives just the right amount of privacy while still letting some light through. It does exactly what I needed it to do and looks so clean and sleek in my space. Perfect balance of style and function — highly recommend!
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Reviewed in the United States on November 7, 2025
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Virginia C.
Alexandria, US
★★★★★ 5
A quick private space
Color: Black, Size: Standard - 4 Panel
Went together easily, just the right height and width for just a bit of privacy.
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Reviewed in the United States on March 3, 2026
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Lexington, US
★★★★★ 5
Versatile Room Divider With Easy Assembly and Strong Coverage
Size: 3 Panel 12FT W
I picked up this Siebwin 3-panel folding room divider mainly for privacy and room separation, and overall it works very well. Assembly is very straightforward, and the divider can be set up, taken apart, and stored without much effort. The fabric quality feels good, and the frame construction is stronger and more stable than expected. The support tubes especially feel well built and help keep the divider standing securely. One feature I really liked is the flexibility of the design. The panels can be used together as a complete divider or separated depending on the setup and available space. That makes it much more versatile for different room layouts or temporary privacy needs. The coverage is also very good, and the size matches the manufacturer’s description accurately. The fabric blocks light and background visibility well enough to provide solid privacy without feeling overly heavy. The wider feet also help improve stability compared to thinner folding dividers. Another positive detail is that everything arrived complete with no missing parts or damaged pieces, which made assembly much easier and faster. Compared to cheaper privacy screens, this one feels more durable and easier to customize depending on the situation. In terms of value for the money, it feels like a very practical and worthwhile purchase considering the size, flexibility, and build quality. Overall, a versatile and well-built room divider with easy assembly, strong privacy coverage, stable construction, complete included parts, flexible panel configuration, and excellent everyday functionality.
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Reviewed in the United States on May 27, 2026
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Fred
New York, US
★★★★★ 5
Stable, flexible in deployment configuration, creates true privacy and looks great.
Size: 3 Panel 12FT W
This is the second room divider panel I have installed, and there are several features about this one that I like much better than my older one. The fact that there are no gaps and that the material is thicker means you get more privacy or more hiding power, if you wish. My older divider has vertical spaces between each of the panels and the panels are half as wide as the Siebwin panels, so there are many vertical spaces. The Siebwin divider really creates privacy. Another feature that I really appreciate is that the legs are wider and stand off from the floor. On my older one the legs are flat and they're rather awkward to adjust because they create more drag on the floor. The feet on the older one also loosen if you turn them counter clockwise, so adjustments of configuration that require the feet to be moved are more complex. The older divider also must be deployed in a zig-zag fashion because he feet are not as wide, but this new one can be deployed and stable in a straight, an "N" shape or an arc. They are both the same length, but because the older one must be use in a zig-zag deployment it doesn't reach to the length of the new one. The Siebwin divider definitely costs more at $103.48, but it sports several features and advantages over the other brand, so it does a better job and is worth the extra cost.
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Reviewed in the United States on May 25, 2026

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