U2 Fasteners

U2 Fasteners makes a lineup of self-tapping construction screws built around one idea: pick the screw by the job and the environment, not by what’s closest on the shelf. The screws are code-compliant for pressure-treated lumber and structural strength, come in 316 stainless steel in the most popular sizes, and include Construction screws that replace lag screws, Universal screws billed as “deck screws on steroids,” Fine trim screws, Cap cabinet screws, and the TopStar adjustable screw that eliminates shimming when hanging doors.

For Montana work, the choice that matters most is corrosion life. Decks, ledgers, fences, and exterior framing all sit through freeze-thaw cycling, and the wrong coating on treated lumber means a fastener that fails long before the structure does. Get the screw type, material, and coating right, and the connection holds for the life of the build.

Pick by Job: The U2 Lineup

Each screw in the range is purpose-built for a class of work. Here’s how they sort out.

Universal Screw. The workhorse. A self-tapping countersunk fastener designed to let the head sit flush with, or slightly below, the surface — giving a stable fastening point and preventing interference where other components rest on the surface. It handles decking, framing, sub-floors, fencing, lattice, shelving, railings, stairs, fine woodworking, lateral bracing, and concrete formwork, and works in wood, particle board, decking materials, sheet metal, fiber cement boards, and melamine. Sizes run #6 through #12, lengths from a half-inch up to 12 inches.

Construction Screw. The structural one. A heavy-duty self-tapping fastener for demanding construction, featuring a finished round Dome head with an extra-large bearing surface under the head to distribute load more evenly. It’s built for staircases, deck frames, rafters, trellis framing, ledger boards, joists, planter boxes, post supports, play-set structures, retaining walls, façade attachments, laminated beams, SIP panels, fencing, pole barns, and concrete forms. This is the screw that snow-load timber framing calls for. It’s positioned as the next generation replacing lag screws. Sizes #10, 1/4”, 5/16”, and 3/8”, lengths from 1 inch all the way to 20 inches.

Fine Screw. For finish work where the head shouldn’t show. Designed for fine woodworking and finish-critical applications where appearance and precision matter, with a slim profile for clean installation in delicate materials. It handles trim, molding, baseboards, crown molding, cabinetry, railings, stairs, siding, PVC trim, and deck rails, and is compatible with pressure-treated lumber when installed per best practices. Sizes #8 and #9, lengths 1 to 5 inches.

Cap Screw. An ideal light-duty interior and exterior screw that makes small projects easier with the draw-down strength of the head and a clean finish.

Re-Fine Screw. With a double twist at the head for drawing strength, it’s built for siding, railing spindles, and small adjustments.

Steel Siding Screw. The metal-roofing and flashing fastener. A trim and flashing fastener for exterior applications needing a low-profile head and integrated sealing, with a white powder-coated head and EPDM washer for a clean look and consistent sealing performance. It’s used in metal siding trim, flashing, and garage door sealing. That EPDM washer is what seals against snowmelt and wind-driven moisture intrusion on metal roofing. Size #10, length 1-1/2”.

A handful of specialty types round out the range. The TopStar adjustable screw eliminates shimming when leveling doors, windows, and cabinets, and the Vinyl Extrusion screw is built for vinyl window retro-fits over old aluminum frames. There’s also a Black Flat Head screw offered in Tapper and Tek point, and a purpose-built TRUSS screw for truss fastening.

Screw Type	Sizes	Lengths	Material Options
Universal	#6, #8, #9, #10, #12	1/2” to 12”	Case-hardened carbon steel, 316 stainless
Construction	#10, 1/4”, 5/16”, 3/8”	1” to 20” (carbon); to 8” (316 SS)	Case-hardened carbon steel, 316 stainless
Fine	#8, #9	1” to 5”	Case-hardened carbon steel, 316 stainless
Steel Siding	#10	1-1/2”	Case-hardened carbon steel

Western Building Center’s U2 stock spans these types — Cap, Fine, and Fine-White trim screws in #8 and #9; Re-Fine screws; and Construction screws (the “CS” line) in #10, 1/4”, and 5/16” across lengths from 1-1/2” through 6”, available in packs and buckets.

Material and Coating: The Choice That Decides Corrosion Life

This is where buyers go wrong. Both the Universal and Construction screws come in either case-hardened carbon steel or 316 stainless steel. Carbon steel covers general interior and exterior work. The 316 stainless — described as 316 marine-grade stainless steel — is the call for superior corrosion resistance in harsh, wet, or coastal-grade conditions. In freeze-thaw country where moisture cycles through a deck or ledger connection year after year, that upgrade earns its keep.

Coating has to match the treated lumber. U2 offers a gold coating approved for ACQ-treated lumber and a black nano coating approved for MCQ-treated lumber — both hexavalent chromium (Cr6+) free — with each coating selected to match the application environment and treated lumber compatibility. On the Fine Screw, there’s also a white nano coating alongside black for MCQ lumber, chosen partly for finished appearance. Match gold to ACQ, black or white to MCQ. Mismatch the coating to the chemistry and you’re inviting the corrosion you were trying to prevent.

The Cr6-free part isn’t just a chemistry footnote. U2 is the first fastener company to offer Chrome 6-free coating, which reduces the risk for end-users who may develop skin cancer through constant use of fasteners with surface coatings containing Chromium 6.

For ground contact — buried posts, retaining wall framing — the gold coating is the rated option. U-Gold coating provides corrosion resistance suitable for use in ACQ pressure-treated lumber at 0.6 pcf for heavy-duty ground contact. That coating was one of the first, if not the only, to pass 2015 requirements with ground contact at 0.6 pcf ACQ treated lumber under ER-454.

One detail worth flagging for finish work: the Cap Screw uses 305 stainless rather than the 316 grade found on the heavier screws — worth noting when you’re spec’ing for a wet exterior cabinetry or trim application.

Code Compliance, Installation, and the Tight Star Recess

For anything structural, the code paperwork matters. U2 released its IAPMO evaluation report (ER-454) to become one of just a few companies evaluated and compliant with the International Building Code and Residential Building Code for corrosion resistance (AC257) and structural strength (AC233). That report covers both the Universal and Construction screws. Supporting technical bulletins cover ledger board to rim board, multi-ply beams, withdrawal and pull-through ultimate values, ASD to LRFD conversion, and ultimate values in concrete. For a deck ledger or a multi-ply beam, those bulletins are the difference between a guess and a verified connection.

Driving these screws is built around one system. The Tight Star Recess grips the U-Bit securely, enabling confident one-handed installation with excellent driving control. Use the matching U-Bit at a controlled speed — the U-Bit and recess design ensures a wobble-free driving experience.

Most of the range is self-tapping. The Tapper Point — Corkscrew Start, Blade Cutting Thread, L-Cuts, and the Bulge — allows fast starts, efficient penetration, reduced splitting, and smoother driving with lower torque in many applications without pre-drilling. But “no pre-drilling” isn’t absolute. With the Fine Screw, depending on material density and edge distance, pre-drilling may be recommended to preserve the finished appearance. The same logic applies anywhere wood is prone to splitting — near ends, near edges, in dense stock.

Seating differs by head type. With the Universal, drive the countersunk head flush to the surface. With the Construction Screw, the Dome head with Talon Grip seats with an extra-large bearing surface under the head and grips the material to prevent loosening.

Frequently Asked Questions

Which U2 screw replaces a lag screw? The Construction Screw. It’s the next generation of construction screws built to replace lag screws — a heavy-duty self-tapping structural fastener with a Dome head and extra-large bearing surface for ledger boards, deck frames, rafters, joists, and post supports. It carries the ER-454 code evaluation, so it’s a verified structural connection, not a substitute by eye.

What coating do I use on ACQ-treated lumber versus MCQ? Gold for ACQ, black for MCQ. U2’s gold coating is approved for ACQ-treated lumber and its black nano coating is approved for MCQ-treated lumber — both Cr6-free — with the coating chosen to match the application environment and lumber compatibility. For buried or ground-contact work, the U-Gold coating is rated for ACQ pressure-treated lumber at 0.6 pcf for heavy-duty ground contact.

Do I need to pre-drill? Usually no. The self-tapping Tapper Point with Corkscrew Start and Blade Cutting Thread is designed for fast starts and reduced splitting without pre-drilling in many applications. Pre-drill when the wood is prone to splitting — and with the Fine Screw, depending on material density and edge distance, pre-drilling may be recommended to preserve the finished appearance.

What screw seals a metal roof or metal siding? The Steel Siding Screw. It has a low-profile dome head and a black EPDM washer for consistent sealing, used in metal siding trim, flashing, and garage door sealing. It comes in #10, 1-1/2” length, with a white or black powder-coated head.

When is 316 stainless worth it over carbon steel? When corrosion exposure is severe. U2 offers 316 marine-grade stainless steel in the most popular sizes, and the Universal and Construction screws both come in that grade. For decks, ledgers, and exterior framing facing repeated freeze-thaw moisture, the stainless upgrade buys corrosion life that a coated carbon screw can’t match in the harshest spots.

Can I drive these one-handed? Yes — that’s the point of the recess system. The Tight Star Recess grips the U-Bit securely for confident one-handed installation with excellent driving control, and the matching U-Bit ensures a wobble-free driving experience. Run a low-speed drill with the correct U-Bit and the screw stays on the bit.