#1 Home Improvement Retailer

Internet # 203533461

Model # 112221

Store SKU # 517498

5/16 in. x 3-1/8 in. Star Drive Washer Head Rugged Structural Wood Screw (45-Pack)

$24.97
  • Easy to install lag screw alternative
  • Integrated washer head allows for maximum clamping force
  • For interior / exterior use
  • View More Details
Store
0 in stock
icon
Free & Easy Returns In Store or Online
Return this item within 90 days of purchase. Read Return Policy
Product Details

About This Product

GRK Fasteners RSS screw is made from Climatek coated and hardened steel. Its sharp threads and point bite instantly into material (including hardwood), reducing the splitting effect caused by smaller shanks. Its washer type head has no sharp edges like conventional lag screws and the added shoulder underneath the washer has the ability to center the RSS screw in predrilled hardware.

Highlights

  • Ideal for ledger boards and more
  • Self-tapping
  • May be used as a lag screw alternative
  • W-cut thread design
  • Return Policy

Product Information

Internet # 203533461

Model # 112221

Store SKU # 517498

Specifications

Dimensions

Screw Length

3-1/8 in

Size

5/16 in

Thread Pitch (mm)

3.5 mm

Threads Per Inch (TPI)

7.2

Details

Drive Style

Torx

Fastener Color

Brass

Fastener Material

Carbon Steel

Fastener Type

Structural Screws

Features

ACQ Rated, Self Tapping

Head Style

Washer Head

Included

Driver Bit

Interior/Exterior

Exterior, Interior

Materials Fastened

Wood to Wood

Measurement System

Inches

Package Quantity

45

Product Weight (lb.)

0.036 lb

Returnable

90-Day

Thread Style

W-Cut Thread

Warranty / Certifications

Manufacturer Warranty

No

Questions & Answers

11Questions
caret
Q:Why are they 3 1/8 inches instead of 3 inches? What is the point of the extra 1/8 inch?
by|Oct 23, 2023
1 Answer
Answer This Question

A:  They are designed to be a code-approved replacement for 16D sinker nails. That's the length needed to meet strength requirements.

by|Nov 14, 2023
    caret
    Q:what kind of sheer strength do these have
    by|May 1, 2022
    1 Answer
    Answer This Question

    A:  The average ultimate shear load for these fasteners is 840lbs.

    by|Jun 13, 2023
      3 found this answer helpful
      caret
      Q:Why is the shank of the screw flared, just underneath the head?
      by|Dec 9, 2020
      1 Answer
      Answer This Question

      A:  If you measure that "flare" you will see that that is the diameter of the lag screw as advertized. For example if you bought 5/16 inch diameter lag screws that is the part that is actually 5/16 and not the entire length of the screw. I suspect that quite a bit of engineering went into the design of these lag screws that make them a lot differant than the old lag bolts. You had to drill pilot holes for the old lag bolts but these you just use your drill driver to install them as the tip actually drills into the wood. Ever since I first tried these new style lag screws I have been so impressed with them that I no longer buy the old style lag bolts.

      by|Jul 13, 2023
      3 found this answer helpful
      caret
      Q:What size Torx/star bit do these 5/16 in. screws use? I'd want to get one that'll lock in to my impact driver.
      by|Mar 5, 2020
      3 Answers
      Answer This Question

      A:  I believe it uses a T30 size bit but when you buy a container of them a free bit is included.

      by|Mar 6, 2020
      1 found this answer helpful

      A:  The bit came in the box of screws. It has "T30" stamped in the side. I hope this helps.

      by|Jun 24, 2020

      A:  Hello I wish all questions were this easy! Take a look in the upper left corner of the package it tells you it's a T-30 bit and one is included.

      by|Mar 7, 2020
        1 found this answer helpful
        Showing 1-4 of 11

        Customer Reviews

        4.9 out of 5

        • 4.9 out of 171 reviews
        • 97% recommend this product
        Filter by:
        Showing 1-10 of 171 reviews
        These are great screws, I used them to hold the sides to outdoor daybed I built. Great, high quality product that I’m glad I found.
        by
        • Verified Purchase
        Do not use on exterior projects or PT wood
        Completely corrodes into rust in a year. I built several projects with GRK and all screws are failing some are so bad the head breaks off. I am going to remove all of them and replace with stainless. Horrible product and waste of time and money.
        by
          15 found this review helpful
          I used these fasteners to hold 4' x 8' sheets of 1/4" peg-board to the wall with nylon spacers be...
          I used these fasteners to hold 4' x 8' sheets of 1/4" peg-board to the wall with nylon spacers behind. Now there are shovels, rakes, pitch-forks and the like hanging on the peg-board. These fasteners might be above and beyond, but I do not have to worry about the things coming off the wall.
          by
          • DIY
          • Verified Purchase
          • Recommended
          1 found this review helpful
          I just had a new pole barn built, and the builders used these screws. It took a bit to find them...
          I just had a new pole barn built, and the builders used these screws. It took a bit to find them, because they are not well advertised, but my wife found them at Home Depot. These screws are awesome. I had some customization on the new barn, so I bought two boxes of these, then 4 more for the farm. I liked the design and performance so well, I bought some #10's for smaller work. These screws drive easy and hold. If you wanted even better hold, get longer screws, but the ones I bought worked great through 2 inch wood. All in all, I can see me switching to these screws over lots of other kinds Phillips head screws.
          by
          • Verified Purchase
          • Recommended
          1 found this review helpful
          Like the screws, T30 tip design doesn't strip out . Threads grab well and using lower speed 1 the...
          Like the screws, T30 tip design doesn't strip out . Threads grab well and using lower speed 1 the torque draws boards up tight. I Used hundred or so on my barn project. Expensive but worth it
          by
          • Verified Purchase
          • Recommended
          GRK fasteners are a superior fastener and ,in my opinion , the best quality and value fastener av...
          GRK fasteners are a superior fastener and ,in my opinion , the best quality and value fastener available today. I have been involved in construction and DIY projects for 60 years (I recently celebrated my 76th birthday). I recently have been installing a small deck in the front of my home. As usual the GRK RSS structural screws I am using for this project meet and exceed my expectations. They bite and drive quickly and have incredible holding power.
          by
          • DIY
          • Verified Purchase
          • Recommended
          1 found this review helpful
          Insanely heavy duty. I'm not a structural contractor or someone who needs these to hold up a hou...
          Insanely heavy duty. I'm not a structural contractor or someone who needs these to hold up a house, but I hung a few heavy shelves by driving these screws into studs. Wow, I'm sure the wall will fall down before these screws give up.
          by
          • DIY
          • Recommended
          3 found this review helpful
          by
          • Verified Purchase
          by
          • Verified Purchase
          Screws are strong and easy to install. Speed start allows one hand installation without having to stabilize screw. Star drive eliminates slipping and stripping of screw.
          by
          • Verified Purchase
          Showing 1-10 of 171 reviews