M-D Building Products (also referred to as M-D Manufacturing) is a family-owned North American manufacturer specializing in home comfort solutions including weatherstripping, floor transitions, door hardware, and aluminum extrusion products. But what Montana contractors really care about are their self-drilling TEK screws — the modified truss head fasteners that save real time on metal framing jobs.
The company serves the home improvement and building materials industries with a focus on domestic manufacturing and quality control. Over 90% of products manufactured domestically in North America means shorter lead times when you need fasteners fast. That matters when you’re trying to close in a project before the weather turns.
The TEK Screws That Matter for Metal Work
Mod’s #8 TEK screws come in three key sizes contractors use: 1/2 inch, 1 inch, and 1-5/8 inch lengths. All feature self-drilling points that eliminate pre-drilling in steel studs, with drill capacity ranging from 0.033 to 0.100 inch (20 to 16 gauge steel).
The real advantage shows up in the specs:
| Specification | #8x1/2” | #8x1” | #8x1-5/8” |
|---|---|---|---|
| Tensile Strength | - | - | 285-550 lbs |
| Shear Strength | - | - | 829-1,096 lbs |
| Torsional Strength | - | - | 42 lb-in |
| Head Diameter | 0.384-0.450 in | - | 0.364-0.440 in |
| Head Height | ~0.102 in | - | - |
The modified truss head provides a larger bearing surface than standard pan or round heads, ideal for thin materials. That extra-wide head prevents crushing when you’re fastening metal lath or thin gauge panels. It’s the difference between a clean installation and material damage that needs fixing later.
Standards compliance includes ASTM C1513 (Cold-formed steel framing), ASTM A510 (Carbon steel), SAE J78 (Performance & dimensional specifications), and ASTM B-117 (Salt spray corrosion resistance). These aren’t just numbers — they mean the screws meet code requirements for structural steel framing applications.
Where These Fasteners Earn Their Keep
Applications include fastening light-gauge sheet metal, attaching metal lath to wood or metal studs in stucco/plaster applications, HVAC ductwork assembly, cabinetry and furniture assembly where low-profile heads are required, and general construction including awnings, door/window frames, and gutters.
The 1-5/8 inch length specifically targets attaching metal lath to 20-16 gauge steel studs in stucco and EIFS applications. That’s critical work in commercial construction where lath attachment failures mean callbacks and warranty claims. Fine threads provide a strong, vibration-resistant connection in metal framing — important when HVAC equipment creates constant vibration.
Zinc plating provides basic corrosion resistance for interior and limited exterior applications. Don’t expect miracles from zinc plating in exposed locations. It’s adequate for Montana’s dry climate in most applications, but use stainless for anything that sees regular moisture.
What Mod Makes Beyond Fasteners
Product categories include weatherization products, flooring products and transitions, door hardware and thresholds, sealants, aluminum extrusion solutions, acoustics products, metal sheets, tools, shower systems, slide-on door bottoms, and weatherstripping. Weatherstripping solutions were the original product that founded the company, dating back to 1920.
Innovation includes 14 patents filed total, including a slide-on door bottom patent. The aluminum extrusion capability sets them apart — vertical integration with aluminum extrusion capabilities means they control more of their supply chain than typical fastener importers.
Target market segments include home improvement retail, professional contractors, DIY consumers, residential construction, and commercial building applications. They’re not trying to be everything to everyone — the focus stays on weatherization and transitions where they’ve built expertise over decades.
FAQ
Q: What makes Mod TEK screws different from standard self-drilling screws?
The modified truss head design sets them apart. Head diameter ranges from 0.364 to 0.450 inches — significantly wider than standard screws. This extra bearing surface prevents thin materials from crushing or pulling through under load.
Q: What gauge steel can these screws drill through?
Drill capacity ranges from 0.033 to 0.100 inch, which covers 20 to 16 gauge steel. That handles most light-gauge metal framing applications. For heavier steel, you’ll need to step up to a different fastener system.
Q: Are Mod screws suitable for exterior use?
Limited exterior use only. Zinc plating provides basic corrosion resistance for interior and limited exterior applications. For any application with regular moisture exposure or coastal environments, upgrade to stainless steel fasteners.
Q: What drive size do these screws use?
Phillips #2 drive is compatible with standard tools and reduces cam-out compared to slotted drives. Keep a good magnetic bit holder — these small screws love to fall into wall cavities.
Q: How does Mod compare to other fastener brands?
Over 100 years of experience and expertise in weatherization gives them credibility, though they’re better known for weatherstripping than fasteners. Over 90% of products manufactured domestically in North America beats most fastener suppliers who import everything. The domestic manufacturing means consistent quality and shorter lead times.
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