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Modified truss head self drilling screws, also called wafer head self drilling screws, with an extra wide integrally formed round washer head, twinfast thread, and self-drilling point.
Modified Truss Head Self Drilling Screws, also called wafer head self drilling screws, are extra wide head twinfast thread self drilling point screws. They feature a wide integrally formed round washer head and a low rounded top around 75% of the washer diameter, generally with a Phillips drive.
Design note: The large washer head offers low clearance and an extra large bearing surface. The usual drive speed for installation is around 2500 RPM.
WIDE WASHER HEAD
Extra wide integrally formed round washer head with low clearance and a large bearing surface for secure clamping.
DRILL POINT & TWINFAST THREAD
Self-drilling point cuts through sheet metal without pre-drilling, and the twinfast double-start thread drives quickly.
Commonly used to attach wire and metal lath to metal studs with a thickness between 12 and 20 gauge. Screws are quenched in liquid and tempered by reheating.
After heat treatment, surface hardness is Rockwell C 50-56 and core hardness is C 32-40, providing a hard cutting edge with a tough core.
✓ Extra wide head
Large bearing surface, low clearance.
✓ Twinfast thread
Double-start thread for faster driving.
✓ Self-drilling point
No pilot hole required in sheet metal.
✓ Phillips drive
Works with standard screwdrivers and drivers.
01 / METAL STUD FRAMING
Attach fittings and lath to metal studs from 12 to 20 gauge.
02 / WIRE & METAL LATH
Secure wire lath and metal lath to steel framing.
03 / SHEET METAL
Fasten light sheet metal components without pre-drilling.
04 / STEEL FRAMING
Steel frame connections in light construction systems.
05 / LIGHT CONSTRUCTION
Cladding, brackets, and accessory fixing on thin steel.
06 / INTERIOR FITTINGS
Interior fittings where a wide head and flush profile are preferred.
| Material Type | Characteristics | Typical Finish |
|---|---|---|
| 10B21 Boron Steel | Cold heading boron steel; hardens well for self-drilling screws. | Blue / white zinc |
| C1018 / C1022 Steel | Carbon steel grades; quenched and tempered for hardness. | Zinc / brass / bronze |
| SS410 Stainless Steel | Martensitic stainless; hardenable with improved corrosion resistance. | Plain / passivated |
Blue / White Zinc
Standard protective zinc plating with bright appearance.
Yellow Zinc
Yellow passivated zinc for improved corrosion protection.
Copper / Bronze
Decorative copper or bronze coating for matching finishes.
Brown / Brass
Brown or brass coating for interior and furniture applications.
Plain / Oiled
Degreased and oiled only for stainless steel or indoor use.
Custom Coating
Special colours and coatings available on request.
Extra Wide Washer Head
Wide integrally formed round washer head with extra large bearing surface.
Low Rounded Top
Low rounded top around 75% of the washer diameter for a compact profile.
Twinfast Thread
Double-start thread drives faster and reduces installation time.
Phillips Drive
Phillips recess provides stable bit engagement during high-speed driving.
Installation note: The usual drive speed is around 2500 RPM. The screw is quenched in liquid and tempered by reheating, with surface hardness HRC 50-56 and core hardness HRC 32-40.
Thread #6 (3.5 mm)Thread #8 (4.2 mm)Length 1/2" - 3"ST4.2 / ST4.8 / ST5.5 / ST6.3Surface HRC 50-56Core HRC 32-40
| Model | Thread Diameter | Note |
|---|---|---|
| #6 | 3.5 mm | Fine gauge lath |
| #8 | 4.2 mm | Standard stock |
| ST4.8 | 4.8 mm | Standard stock |
| ST5.5 | 5.5 mm | Standard stock |
| ST6.3 | 6.3 mm | Heavier gauge |
Lengths range from 1/2" to 3" (13 mm to 76 mm). Other diameters and lengths are available on request.
Kraft boxes
With inner partitions, thread protection and full labeling.
Bulk cartons
Five-layer corrugated, waterproof sealed and strapped.
Pallets / wooden cases
ISPM-15 heat treatment certification available.
Resealable polybags
For samples and low-volume orders.
VCI anti-rust packaging
For long-distance overseas shipment.
Custom OEM packaging
Labels, barcodes and packaging; MOQ may apply.
01 Raw Material Inspection
02 Wire Drawing
03 Cold Heading
04 Thread Rolling
05 Drill Point Forming
06 Quenching
07 Tempering
08 Surface Finishing
09 Hardness Inspection
10 Dimensional Inspection
11 Packaging & Labeling
12 Outgoing QC
Hardness testing
Surface hardness HRC 50-56 and core hardness HRC 32-40 verified by Rockwell test.
Dimensional inspection
Head diameter, head height, thread pitch, point geometry and length per drawing.
Thread verification
GO/NO-GO gauges and sample drilling and drive tests.
Coating thickness
Magnetic or eddy-current measurement; salt spray per ASTM B117.
Material certificate
Chemical composition and heat/lot traceability on request.
Final verification
100% visual inspection, packaging check and traceability.
1. What is a trus head or wafer head screw?
It is an extra wide head screw with an integrally formed round washer head and a low rounded top around 75% of the washer diameter, generally with a Phillips drive.
2. What is it commonly used for?
Attaching wire and metal lath to metal studs with a thickness between 12 and 20 gauge. The large washer head gives low clearance and an extra large bearing surface.
3. What materials are available?
10B21 boron steel, C1018/C1022 hardened carbon steel, and SS410 martensitic stainless steel.
4. What sizes are available?
Thread #6 and #8 (3.5 mm or 4.2 mm), with lengths from 1/2" to 3" (13 mm to 76 mm). ST4.2, ST4.8, ST5.5, and ST6.3 models are available.
5. What surface treatments are available?
Blue or white zinc, yellow zinc, copper, bronze, brown, and brass coating.
6. What is the hardness after heat treatment?
Screws are quenched in liquid and tempered by reheating. Surface hardness is Rockwell C 50-56 and core hardness is C 32-40.
