Joist screw | C3

Beam screw in corrosion class C3 is a high-quality fastening component designed to withstand moderate corrosion in outdoor environments and industrial applications. The screw is self-drilling with a #5 drill point (4–12.5 mm), which provides quick and easy single-step installation.

AREA OF USE

Intended for mounting roof and wall cladding onto heavy steel beam structures. Benefits include high strength, reliability, and easy installation, making it ideal for construction projects where durability is a requirement.

TECHNICAL SPECIFICATIONS

Product type: Beam screw
Thread type: Thread-forming
Surface treatment: C3-rated coating
Head shape: Hexagon
Drilling capacity: 4–12.5 mm

FREQUENTLY ASKED QUESTIONS (FAQ)

What does it mean that the beam screw has a #5 drill point and what material thickness can it handle?

Drill point #5 is a heavy-duty, extended drill point designed for direct fastening into heavy structural steel and beam profiles without pre-drilling:

• Handles extreme material thickness (4–12.5 mm): The extra-long cutting zone drills through heavy steel beams (e.g., IPE, HEA, UNP) and thick steel profiles in a single operation before the threads begin to engage.

• Time-saving single-step installation: You avoid work steps involving pre-drilling, changing drill bits, or making holes with core drills. Drilling, thread forming, and fastening happen continuously in one and the same operation.

• Integrated chip breaking: The geometry of the drill point is designed to effectively transport away steel chips during drilling so that the threads do not seize.

What does Corrosion Class C3 mean and where can the screw be used?

Corrosion class C3 covers environments with moderate corrosion exposure and humidity:

• Outdoor applications: Suitable for steel structures outdoors in cities and industrial areas with moderate amounts of air pollution, as well as coastal areas with low salinity.

• Indoors with condensation: Fits excellently in untreated spaces with moisture and condensation, such as warehouses, breweries, laundry rooms, and agricultural buildings (without high levels of corrosive ammonia gases).

• Long-lasting surface protection: The screw is equipped with a high-performance surface layer (often zinc-nickel or a special coating) that passes tough salt spray tests to preserve its mechanical load-bearing capacity.

How is a self-drilling beam screw correctly installed in heavy steel?

1. Use the right machine and speed: Use a powerful cordless screwdriver or impact wrench adapted for steel construction. Adjust the speed down (recommended approx. 1,000–1,500 rpm) so that the drill point has time to cut without the friction heat destroying the hardness of the drill point.

2. Sufficient drilling pressure: Use a firm and even pressure against the beam during the drilling stage so that the tip continuously removes material.

3. Check sealing and tightening: Release the pressure when the screw head reaches the surface and avoid over-tightening the screw, so that the thread in the steel is not damaged and any sealing washer is not crushed.