Spax and GRK are two types of screw brands that are self-countersinking and do not require pre-drilling. Both brands have virtually dozens of screw types designed specifically for a wide range of applications such as drywall, ceiling, fences, roof trusses, window installations, and more.
For those exploring these premium construction screws, this review highlights both Spax and GRK’s multi-purpose screws, and hopefully provides enough information for you to make a decision about which brand is best for you.
The Germany-based company Altenloh, Brink & Co. has been manufacturing wheel bolts and engineered fastening solutions since it was founded in 1823.
In 1967, the company launched its innovative line of multi-material construction fasteners called Spax. The brand and its multi-purpose screws were introduced to the U.S. market in 1997 and have since been sold in hardware and home improvement centers nationwide.
SPAX® Multi-Purpose Construction Screws are engineered fasteners that work for both interior and exterior applications, including wood, sheet metal, plastic, concrete and masonry.
There are other SPAX® screws, like the POWERLAGS®, which were manufactured specifically for structural exterior and interior wood-to-wood connections, or specialty engineered fasteners made for hardwoods, medium density fiberboards, wood decks, cabinetry, and many more.
Glenview, Illinois-based company Illinois Tool Works, Inc. (commonly called ITW) was founded in the early 1900s and has been acquiring tools like washers, wafer cutters, plastic fasteners, and other miscellaneous tools for automotive applications from other companies and inventors. TW expanded to other industries including defense, computer and construction with the launch of the company’s first self-drilling screw in the 1960s.
In 1990, Uli Walther and his family built the GRK brand from scratch and brought the “industry’s toughest screws” into the limelight. The business was unique in that each product launched included at least one proprietary patent, such as the Climatek technology (used by the Navy to keep corrosion at sea).
In 2011, ITW acquired another major brand – the Canadian GRK that Uli Walther and his family had been running since 1990 in Thunder Bay, Canada.
GRK also has a store-full of screws and fasteners, but the R4 Multi-Purpose Climatek GRK Screws is the company’s most popular and best-selling screws.
Spax vs. GRK: Cost Comparison
A 50-pack of GRK R4 Multi-Purpose Climatek GRK Screws is around $26, which is about 25% more expensive than ordinary screws.
The cost of Spax Multi-Purpose Construction Screws depends on the length and type of screw you buy, but typically comes out at around $1 a piece for a medium-sized screw.
The price of GRK fasteners and Spax screws also depends on the type of head screws (flat, wafer head, pan head, washer head, etc.), the length and thickness of the screws, coating options (determines resistance to corrosion), as well as whether you’re buying them in bulk (sometimes in pails of 1,500 pieces) or in retail (100 pieces or less).
Spax vs. GRK: Warranty Comparison
GRK Fasteners have a limited lifetime warranty, wherein the company is willing to replace any defective screws as long as they are not damaged due to improper installation, improper use, neglect, alteration, accident, or misuse. GRK’s PHEINOX™ stainless steel screws also come with a limited lifetime guarantee against staining and rusting.
Spax screws have a similar limited lifetime warranty with GRK, but an added corrosion protection guarantee for screws with either zinc or WIROX coating.
Almost all Spax and GRK screws are engineered out of hardened steel, so they really wouldn’t shear off under typical applications.
Spax vs. GRK: Design & Quality comparison
SPAX engineered fasteners are multi-purpose fasteners for interior or exterior applications. They are heat-treated to Grade 5 durability and designed with 4CUT point (which keeps boards from splitting) and patented thread serrations that require 40% less torque when installing.
Screws with SPAX’s proprietary HCR-X™ coating are rust-resistant and protect lumber, sheet metal, plastic, concrete and other materials. SPAX screws, which are available in a wide range of sizes, are very strong and durable. They can be driven in most hardwoods and concrete without breaking, but have impressive holding power. Plus, SPAX screws absolutely zero pre-drilling.
GRK fasteners are self-countersinking, which means they can drill a perfectly clean screw hole even on the hardest woods with screw heads that close the hole off with precision. They’re designed with CEE thread that enlarge the screw hole and reduce friction on the screw shank, lowering the driving torque as a result.
GRK R4 Multi-Purpose screws are manufactured with 60% Climatek™ coating, which makes these premium screws resistant to salt spray, heat, cold, water, wind and other harsh elements that normal screws cannot withstand.
Spax vs. GRK: Installation comparison
Spax screws and GRK fasteners are usually included with either a Torx T20 or T25 bit, which features star-shaped cross sections for a better connection with the screw head.
Using these premium screws is slightly different from using standard screws, since the serrated threads by the tip of the screws cut wood and other materials like a saw. This means you no longer have to bore a pilot hole or worry about splitting the board drilling in a screw.
Some GRK fasteners even have threads on both the tip and shank, working double-time to make the hole slightly larger, more quickly and more precisely.
Spax vs. GRK: Final Showdown
Spax and GRK multi-purpose screws are more expensive than the regular screws from your local hardware, but they serve a specific purpose. Using either Spax and GRK screws means you can use them without pre-drilling which will save a lot of time and guarantee a better product. Not all of the screws are specifically heavy duty (some types of screws are only for interior use), but these premium screws are extremely durable.
Each brand has a handful of variations, so choose wisely based on your needs. For example, Spax’s yellow-zinc screws are cheaper than GRK, but they are only for interior applications and not designed for extreme exterior conditions like GRK’s yellow fasteners.
It can be confusing if you’re new to these premium brands of screws (it’s why both Spax and GRK have a guide to help you find the right screw or tool). However, once you’ve found specific sizes for your projects, there’s a good chance you’ll be using them for years to come.