Evolution BMHH5.5-38-3 Bi-Metal 38mm Tec Screws for Light Section Steel (Box of 200) by Evolution Fasteners

The Evolution BMHH5.5-38-3 Bi-Metal Tek Screw is a high-quality 5.5 x 38 mm self-drilling screw engineered for light section steel applications. It features a bi-metal construction – a stainless steel body for superior corrosion resistance combined with a hardened carbon steel drilling tip – allowing it to cut through steel without pre-drilling. With its hexagonal head (5/16" drive) and twin coarse threads, this screw provides strong, secure fastening of metal panels and sheets to steel supports. Supplied in a box of 200, it offers reliable performance for both indoor and outdoor construction projects where durable stainless steel fixings are required.

Key Features

• Bi-Metal Construction: Stainless steel shank (A2 grade 304) for long-lasting corrosion resistance, fused with a hardened carbon steel tip for efficient self-drilling.
• Self-Drilling Tek 3 Point: Integrated Tek 3 drill point easily penetrates light-gauge steel (up to 4.0 mm thick) without the need for pre-drilling, saving time and effort during installation.
• Hexagonal Head: 5/16" (8 mm) hex head for high torque driving and a secure grip. Ensures easy installation with standard hex driver bits and provides a flush, neat finish when tightened.
• High Holding Power: Twin coarse thread design for fast engagement and strong holding in thin metal sections, preventing strip-out and ensuring a tight clamp on connected materials.
• Zinc-Plated Finish: Electroplated zinc coating over the drilling tip and threads provides additional protection against rust and wear, enhancing durability especially in outdoor environments.
• Bulk Packaged: Supplied in a box of 200 pieces for convenient bulk use on site, reducing the need for frequent reordering and ensuring you have plenty of screws for larger projects.

Applications

• Light Section Steel Fabrication: Ideal for fastening thin steel sections, such as purlins, girts, or light-gauge framing members, in building construction and metal fabrication.
• Cladding and Sheet Installation: Designed for securing metal cladding panels, siding sheets, and aluminium profiles to steel frameworks (e.g. fixing aluminium sheeting and panels to steel supports).
• Exterior Projects and Corrosive Environments: Suitable for use in outdoor construction, coastal projects, or any application where a stainless steel fixing is required to prevent corrosion.
• General Purpose Metalwork: Useful for HVAC installations, fencing, enclosures, and assembling components to steel where self-drilling capability and corrosion resistance are essential.

Essential Specifications

• Screw Dimensions: 5.5 mm diameter x 38 mm length
• Head Type: Hex head (5/16" across flats), unwashered
• Drill Point: Tek 3 self-drilling point (hardened carbon steel)
• Drilling Capacity: 1.2 mm – 4.0 mm steel thickness (light gauge steel)
• Thread Type: Twin coarse thread for rapid fastening
• Material: A2 stainless steel shank (AISI 304) with carbon steel tip
• Finish: Zinc-plated for additional corrosion protection
• Tensile Strength (approx): 14.4 kN; Shear Strength (approx): 10.8 kN (as per manufacturer data)
• Recommended Drill Speed: 1,500 – 2,500 RPM for optimal drilling performance
• Packaging: Box of 200 screws for trade and site use, ensuring ample supply for your project.