Hillman 5/16 in. Diameter x 3-1/2 in. Length Heat-Treated Steel Hex Head Cap Screw, 50-Pack
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
Save 10%

Shipping Estimate
USA
  • USA
  • CAN

Ships within 48 hours · Estimated delivery Jul 9 - Jul 14

Promo Codes Available:

For Your Every Summer RSVP, with Code: SUMMER15

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

Discover Niche Categories That Outsell

Top-Converting Item to Boost Your Average Order

4.8 ★★★★★
Based on 1162 reviews
Sort
Highest Rating
Newest First
Oldest First
Product Reviews
K
Verified Purchase
Kevin March
Natrona Heights, US
★★★★★ 4
Great product
Size: Large, Color: (035) Steel / White / Black
Comfortable fit perfect
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on March 15, 2026
W
Verified Purchase
Wesley
Lexington, US
★★★★★ 5
Quality No Show Socks That Are Comfortable and Durable
Size: Large, Color: (100) White / White / Black
These Under Armour no show socks are great for everyday training and casual wear. The cotton blend feels comfortable and they stay in place throughout the day. Getting six pairs in a pack is solid value for a quality brand. They hold up well after multiple washes and the no show style works great with most athletic shoes. A reliable go-to sock.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on April 30, 2026
H
Verified Purchase
Hanson
Lowell, US
★★★★★ 5
Comfortable
Size: Large, Color: (001) Black / Black / White
I recently picked up a pair of Under Armour socks, and they’ve quickly become my go-to choice for daily wear and workouts. From the first wear, the fit felt snug and supportive without being too tight. The fabric is lightweight yet durable, and it does a great job wicking sweat — keeping my feet dry even during longer runs or intense gym sessions. One of the things I appreciate most is the arch support and cushioning in the right places. It adds just enough padding where I need it, especially under the ball and heel of the foot, which makes a noticeable difference on days when I’m on my feet a lot. The socks also have a nice breathable mesh pattern that improves airflow.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on January 4, 2026
N
Verified Purchase
no body!
Pawtucket, US
★★★★★ 5
Perfect fit
Size: Large, Color: (100) White / White / Black
Durable and comfortable. Size works well. Very soft with nice thickness for training. Fairly long lasting
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on February 12, 2026
Q
Verified Purchase
Quick Reviews
Dallas, US
★★★★★ 5
Post-COVID Sock Hunt: Finally a Win
Size: Medium, Color: (001) Black / Black / White
Ever since COVID, I haven’t been able to find a pair of socks that hold up for more than a few months. Brands like UA, Adidas, and others seem to have cut corners—likely in response to inflation—by downgrading materials and labor rather than raising prices. The result? Socks that wear thin, rip easily, or lose shape fast. These, however, have been a pleasant surprise. I’ve been wearing them for a few weeks and so far, they’re holding strong. You can tell some cost-saving measures were still made—certain areas feel slightly thinner—but overall, the construction is solid. A key win: they stay on. These are ankle socks (not “no-shows”), and they hug the ankle securely. That’s a huge plus in a world where most post-COVID no-shows slide off halfway through the day. We may never get back to the pre-COVID quality standards without paying a premium, but for now, these are a reliable choice. Ratings: • No slipping: 10/10 • Price: 7/10 • Durability (so far): No pilling or loose threads — promising start.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on March 24, 2025

recommand products