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GRK screws

The Ultimate Guide to GRK Fasteners for Professional Remodelers

Looking for GRK screws and GRK fasteners? Choosing the correct fasteners for an application can be the difference between a project that stands strong for years to come and one that loosens and falls apart over time.

Professional remodelers and contractors know that quality and longevity have a lasting impression on their brand and business. To produce consistently excellent results and keep customer referrals coming in, they need to ensure they have the highest quality supplies.

GRK fasteners and RSS structural screws have been trusted for over 25 years as the industry leader in this category. This guide outlines the uses and benefits of each type of unique fastener they manufacture.

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Table of Contents:

Introduction: How it All Started

GRK Caliburn Concrete Screws

GRK FIN/Trim Screws

GRK Low Profile Cabinet Screws

GRK R4 Multi-Purpose Framing Screws

GRK MSS Metal Siding Screws

GRK RSS Structural Screws

GRK RT Composite Trim Screws

GRK Top Star Shim Screws

Conclusion: Find Fasteners Fast with USTF

Introduction: How it All Started

GRK began manufacturing "The Industry's Toughest Screws" in 1990. Early on, the company worked tirelessly to build relationships with reputable wholesale partners and material retailers internationally.

The business grew rapidly due, in large part, to the uniqueness of GRK's products. Every GRK fastener features at least one proprietary patent, and the company is continuously designing and testing its products to innovate their already high-performing screws and fasteners.

One such innovation was the development of Climatek technology. Originally designed for the Navy to prevent corrosion at sea, Climatek is now used exclusively on GRK products to provide superior protection and longevity.

Today's professional remodelers and contractors swear by GRK fasteners, such as the remodeling business owner who posted this review:

"We have been using GRK's for the last year and they are a very strong fastener that is also quick to install." - Thomas V.

GRK products have earned a reputation for durability and reliability.  GRK screws all have a specific purpose. They are engineered to master that application better than any other fastener.

One customer had this to say about GRK RSS 5/16 x 6":

“I've used different types of wood fasteners before for my deck, but these ones are exceptional. Drive easily into the wood and don't break. The Torx head is a definite plus as it transfers the torque effectively and does not strip the head. I definitely will use again if needed.”

No matter the application, you can trust GRK fasteners to get the job done quickly and securely.

GRK Caliburn Concrete Screws Concrete and masonry fasteners

GRK Caliburn Screws securely attach materials and fixtures to concrete surfaces. Caliburn screws are made of high carbon steel and are Climatek coated to resist corrosion. Their patented thread design easily drives through concrete, and the GRK screws are durable enough to be removed and reinserted multiple times without breaking or wearing. For example, the diagram below shows the proper installation of Caliburn XL Concrete Screws.


Professional contractors have shared the following praise for GRK Caliburn screws:

“Best concrete/stone screws ever. I used them to screw down EP Henry paver steps. They worked perfectly where the best adhesives made specifically for the job had failed.” - Jim R.

“Good strength into concrete. Installed over 400 and had only one head snap off. I will use again without question!” - Gene M.

Caliburn Flathead Concrete Screws

Caliburn Flathead Concrete Screws feature a self-anchoring system that makes installation fast and easy. Their heavy-duty threads are best suited for securely attaching wood to concrete. They are compatible with T-30 star drive drill bits. We recommend pre-drilling with a 3/16 bit where possible.

Caliburn Flathead

GRK Caliburn Flathead Concrete Screws: ¼” x 1 ¾” | ¼” x 2 ¼” | ¼” x 2 ¾” | ¼” x 3 ½” | ¼” x 5”

Caliburn Panhead Concrete Screws

Caliburn Panhead Concrete Screws possess all of the great benefits of the original Caliburn flathead screws, but with the pan head's added appeal, which lends itself well for exposed finish looks. They are compatible with T-30 star drive drill bits, and pre-drilling with a 3/16 bit is best.

GRK Caliburn Panhead Concrete Screws: ¼” x 1 ¾” | ¼” x 2 ¼”

Caliburn Panhead

Caliburn XL Concrete Screws

Caliburn XL is the third style of Caliburn fasteners and features a washer head style. Their design gives them superior holding power for applications such as basement framing. Caliburn XL Concrete Screws are compatible with T-40 star drive drill bits, though pre-drilling with a 1/4 bit is ideal.

GRK Caliburn XL Concrete Screws: 19/64 x 2 ¾” | 19/64” x 3 ½” | 19/64” x 5”

Caliburn XL

GRK FIN/Trim Screws - Fine carpentry fasteners

GRK FIN/Trim Screws have the smallest screw head on the market and range in length from 1 ¼" to 5". They work for interior applications such as trims, crown molding, and GRK cabinet screws. They also simplify exterior projects such as deck rails, stairs, and railings.


The patented Zip-Tip head design makes pre-drilling optional, and its incredibly small size makes the head virtually disappear when countersunk. A pro-tip for using GRK FIN/Trim Screws is to drive at half-speed for a perfect finish every time. These GRK screws are compatible with T-10 star drive drill bits, and pre-drilling is unnecessary. 

GRK FIN/Trim Screws: #8 x 1 ¼” | #8 x 1 ½” | #8 x 2” | #8 x 2 ½” | #8 x 2 ¾” | #8 x 3 ⅛” | #9 x 4” | #9 x 5”


PHEINOX Stainless Steel Screws

PHEINOX Screws are made from the highest quality 305-grade stainless steel wire, maximizing their torque and strength. The patented Climatek coating of these screws makes them ideal for use around pools, decks, and hot tubs.

In addition to excellent rust resistance, they are also a great choice for use in highly acidic woods such as redwood and cedar. Like all FIN/Trim Screws, you should drive PHEINOX Stainless Steel Screws at half-speed. They are compatible with T-10 star drive drill bits, and pre-drilling is unnecessary.

GRK PHEINOX FIN/Trim Screws: #8 x 1 ½” | #8 x 2” | #8 x 2 ½” | #8 x 3 ⅛” | #9 x 2 ½ | #9 x 3 ⅛”


White FIN/Trim Screws

GRK FIN/Trim Screws are available in a white Climatek finish to seamlessly match your project's overall finish. These screws are particularly useful for door and window trims, crown moldings, and GRK cabinet screws. They are compatible with T-10 star drive drill bits, and pre-drilling is unnecessary.

GRK White FIN/Trim Screws: #8 x 2” | #8 x 2 ½”

White FINTrim

GRK Low Profile Cabinet Screws Cabinet and vinyl siding fasteners

GRK Cabinet Screws are primarily used for cabinet construction and installation since they are adept at preventing splitting. However, we suggest vinyl siding due to its small diameter and drawing power.

Low Profile

Low Profile Cabinet Screws are strong enough to provide a strong and secure installation but are thin enough at 4mm to prevent your materials from splitting. They feature a built-in washer head that presses flat and seamlessly blends into any surface. Their W-Cut threads reduce torque, and their self-tapping design eliminates the need for pre-drilling. They are compatible with T-15 star drive drill bits.

GRK Low Profile Cabinet Screws: #8 x 1 ¼” | #8 x 1 ½” | #8 x 1 ¾” | #8 x 2” | #8 x 2 ½” | #8 x 2 ¾” | #8 x 3 ⅛”



Cabinet Stainless Steel Screws

PHEINOX Cabinet Screws are only available in #8 x 1 ¼", whereas the other GRK Low Profile Screws are available in wider sizes. These GRK screws harness the strength and durability of stainless steel for cabinetry applications, maximize torque, and provide unmatched overall performance.

As with all PHEINOX screws, PHEINOX Cabinet Screws are best for wet environments such as exterior projects around decks, pools, and hot tubs. These screws are highly resistant to corrosion for GRK cabinet screws, making them perfect for highly acidic substrates, including redwood and cedar. They are compatible with T-15 star drive drill bits, and pre-drilling is unnecessary.

Low Profile PHEINOX

White Low Profile Cabinet Screws

GRK Low Profile Cabinet Screws are available in a white Climatek finish which is perfect for blending into the surface of your project. You can also use low Profile Cabinet Screws for light-duty framing applications where the white finish also comes in handy for a clean and smooth result. They are compatible with T-15 star drive drill bits, and pre-drilling is unnecessary.

GRK White Low Profile Cabinet Screws: #8 x 1 ¼” | #8 x 1 ½” | #8 x 2 ½” | #8 x 3 ⅛”

White Low Profile

GRK R4 Multi-Purpose Framing Screws Highly versatile fasteners

GRK R4 Multi-Purpose Framing Screws work effectively in numerous materials, including wood, particleboard, laminate decking, melamine, cement fiberboard, and even sheet metal. They are even useful in projects that use pressure-treated lumber.

R4 Screws don't require pre-drilling and can prevent splitting for precise, clean holes. GRK elaborates on the unique properties of R4 Screws in their US Distributor Catalog, stating:

“GRK's R4™ self-countersinking screw has a patented underhead with saw-blade like cutting teeth and six self-contained cutting pockets. Together they act similar to a circular saw-blade, transporting the drill dust away from the edge of the screw hole while cutting a perfectly clean hole into even the most brittle materials without cracking any surface treatment.”

R4 Multi Purpose

These unique design features of the R4 make it a top choice amongst professional remodelers and contractors. One customer who purchased GRK R4 #9 x 2 ½" commented:

“These GRK fasteners are amazing! They'll save you a ton of time and you won't have to worry about wood splitting when screwing in on an edge as these fasteners boar their own hole. US Tool & Fastener co. is great. They were very helpful when I called with questions about my product and I received my order within 1 day.”

Since GRK R4 Screws are popular for many different projects, they are available in various sizes and pack sizes. The #6 and #8 sizes are compatible with T-15 star drive drill bits, while the #9, #10, and #12 sizes are compatible with T-25 drill bits.

GRK R4 Multi-Purpose Framing Screws: 

PHEINOX R4 Stainless Steel Screws

As with the other R4 Screws, PHEINOX R4 Screws are self-countersinking, which allows them to cut a perfectly clean hole that leaves no damaging dust or fibers around the head. This technology also makes drilling into hardwoods like oak and birch faster and easier since they can install without separately countersinking. PHEINOX R4 Screws are compatible with T-25 star drive drill bits.

GRK PHEINOX R4 Screws: #9 x 2” | #10 x 2 ½” | #10 x 2 ¾” | #10 x 3 ⅛” | #10 x 4”


GRK MSS Metal Siding Screws Ultra corrosion-resistant fasteners

GRK MSS Screws, as seen in GRK's US Distribution Catalog, provide exceptional resistance to corrosion and maximum strength attachment security. Metal Siding Screws feature an integrated washer head complemented by a rubber washer below. This addition allows MSS Screws to completely seal off drill holes, making them a great option for exterior projects facing sun exposure, precipitation, and other elements.

You can use MSS Screws for interior and exterior applications, but they are most common in projects like metal siding installation and garage door trims. They are compatible with T-25 star drive drill bits, and pre-drilling is optional.

GRK MSS Metal Siding Screws: 9” x 1 ½” | 9” x 2”

MSS Screws

GRK RSS Structural Screws Hardened steel structural fasteners, Lag screw alternatives

GRK RSS Screws are used for structural applications, including ledger boards, carrying beams, deck posts, stair rails, and other interior and exterior structures. RSS Screws are preferred to traditional lag screws for professional remodelers because the CEE thread enlarges the screw holes to reduce splitting.

Other benefits of RSS Screws over conventional lag screws are their washer head type that does not have sharp edges, and their nominal diameter helps center them in pre-drilled hardware such as hinges.

RSS Screws

In a review of GRK RSS ¼” x 2”, one remodeler shared three observations:

“1. Love GRK's. They make construction so much easier when their use is appropriate. 2. USTF has the biggest range of their products, many I cannot get locally 3. Purchasing from them was easy and quick, I'll keep shopping here.”

Another customer shared their experience with GRK RSS 5/16” x 6”:

“I recently used GRK RSS screws in lieu of using lag bolts to stabilize the guard railing and baluster panels of a deck. Installation was easy and fast and the RSS screws tightened the railings beautifully!”

RSS #10 and ¼" are compatible with T-25 star drive drill bits; 5/16" and ⅜" are compatible with T-30 star drive drill bits; ⅜" are compatible with T-40 star drive drill bits. No pre-drilling is mandatory for faster penetration.

GRK RSS Structural Screws:


PHEINOX RSS Stainless Steel Screws

PHEINOX RSS Screws are so corrosive and high-performing that GRK offers a lifetime guarantee against staining and rusting. They come from hardened steel for optimum strength and durability, and their corrosion resistance makes them a great option for projects in coastal areas and below ground.

PHEINOX RSS Screws ¼" are compatible with T-25 star drive drill bits, while 5/16" are compatible with T-30 star drive drill bits.

GRK PHEINOX RSS Screws: ¼” x 1 ½” | 5/16” x 2 ½” | 5/16” x 3 ⅛” | 5/16” x 4” | 5/16” x 5 ⅛” | 5/16” x 6”


RSS JTS Joint & Truss Screws

GRK JTS Screws are incredibly heavy-duty fasteners for roof and floor construction. They are also frequently used in ledger boards, retaining walls, and log and timber framing projects. The threads of these screws are very sharp, allowing them to cut into materials - even hardwood - without splitting instantly.

JTS Screws have a rounded head with a built-in shield that provides a finish free of sharp edges, unlike conventional lag screws. They are compatible with T-25 star drive drill bits.

GRK RSS JTS Joint & Truss Screws: ¼” x 5” | ¼” x 6 ¾”

JTS Screws

GRK RT Composite Trim Screws Composite, PVC, and fine carpentry

GRK RT Composite Trim Screws are essentially FIN/Trim screws but with reverse threading under the head. That threading allows the screws to work well in composite and cellular PVC trim. GRK describes the benefits of this unique design feature as such:

“Based on extensive tests, GRK has found that the reverse thread helps the screw head disappear beneath the surface of the classic wood composite material, reducing or eliminating the dimple that sometimes appears when using the FIN/Trim™ screw.”

RT Composite Trim

A pro remodeler said the following in their review of GRK RT Composite Trim Screws #8 x 2 ½”:

“These screws are small-headed and bury themselves easily into composite boards. Using the GRK bits gives me the most life for installing. Good products!”

RT Composite Trim Screws' heads disappear when countersunk, leaving a smooth finish at the end of your project. The #8 sizes are compatible with T-10 star drive drill bits, and the #9 sizes are compatible with T-15 star drive drill bits. No pre-drilling is necessary as with the original FIN/Trim GRK Screws.

GRK RT Composite Trim Screws: #8 x 2” | #8 x 2 ½” | #8 x 3 ⅛” | #9 x 2 ½” | #9 x 3 ⅛”



PHEINOX RT Stainless Steel

All RT Screws, including PHEINOX RT, are approved for use with pressure-treated lumber. PHEINOX RT Screws #8 varieties are compatible with T-10 star drive drill bits, and the #9 sizes are compatible with T-15 star drive drill bits. The #8 x 2" and #8 x 2 ½" are also available with whiteheads.

GRK PHEINOX RT Screws: #8 x 2” | #8 x 2” w/ White Head | #8 x 2 ½” | #8 x 2 ½” w/ White Head | #8 x 3 ⅛” | #9 x 2 ½” | #9 x 3 ⅛”


RT White Composite Screws

RT White Composite Screws blend in seamlessly with white decking and other materials. They use case-hardened steel for maximum attachment strength and pressure-treated lumber use.

RT White Composite Screws are available in #8 sizes and are compatible with T-10 star drive drill bits.

GRK RT White Composite Screws: #8 x 2” | #8 x 2 ½” | #8 x 2 ¾” | #8 x 3 ⅛”

White RT

GRK Top Star Shim Screws Shim-free installation

GRK Top Star Adjustable Shim Screws eliminate the need for shims when installing wooden doors and windows. Their unique design features a screw within a screw that makes for easy adjustments with minimal labor. They are white zinc plated for exceptional longevity and can be adjusted quickly, even years after installation.

Top Star Shim Screws

After pre-drilling with a 5/16" bit, Top Star Adjustable Shim Screws are installed using a Top Star Crown Bit for completely plumb installation. They are also compatible with T-15 star drive drill bits.

GRK Top Star Shim Screws: ¼” - ⅜” x 2 ½” | ¼” - ⅜” x 3 ⅛”


Conclusion: Find Fasteners Fast With USTF

Our highly skilled experts are available to answer your questions about GRK screws, RSS structural screws, or any other fasteners. We pride ourselves on providing quick, knowledgeable responses in addition to our fast, free shipping.

But don't just take our word for it. Here's what one professional remodeler had to say after ordering GRK R4 #8 x 1 ½":

“Best fasteners that I have used in over 40 years of building barns, decks, sheds, etc. The shipping from USTF was next day and free. You can't get any better service than that.”

Another satisfied pro commented:

“Could not get GRK SS screws locally in the length I needed so I tried USTF. The process was simple, fast and effective. Screws arrived when I needed them and the new dock is not completed. Would recommend USTF in the future.”

Contact us online or call 877-777-4717 today! You can also follow our Instagram for exclusive product deals and promotions from our catalog.

The Ultimate Garage Workshop: Layout and Tools Guide BLOG

17 May 2022

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