Meet Malco Zip-In HW6X3/8Z Self-Piercing Screws—the fast, dependable solution for joining thin sheet metal with precision. This 6x3/8" self-piercing screw features a zinc-plated finish and a 1/4" slotted hex washer head, designed for quick, secure fastening in metal enclosures, HVAC ductwork, automotive panels, and more.

• Unique thread design for instant bite: A single starting thread is formed down to the very tip of the point, the source of Zip-In's penetrating power from the first contact.
• Double-thread engagement for rapid penetration: A second thread above the point engages after initial penetration, drilling in double fast for efficient installation.
• Heat-treated for sharp, durable points: A sophisticated heat-treat process tapers to a fine, sharp point without sacrificing critical point strength.
• Faster driving and heavier-gauge capability: The Zip-In design delivers quicker fastening and greater capacity for heavier gauges of sheet metal than any other self-piercing type.
• Corrosion-resistant finish: Zinc plating protects against rust in exposed or humid environments, helping maintain long-term performance.
• Bulk quantity for large projects: Packaged in a generous 18,000-count bundle, ideal for continuous work on multiple panels or installations.

Ideal use cases

• HVAC ductwork and metal housings where fast, reliable piercing is essential.
• Automotive body panels, instrument enclosures, and electrical cabinets requiring consistent bite and strong pull-out resistance.
• Metal roofing, siding, and panel assemblies that demand a robust self-piercing fastener with rapid installation.

Why choose Zip-In over traditional self-piercing screws? The combination of the tip-first thread, second-thread engagement, and optimized heat treatment translates to faster, cleaner assemblies with fewer misdrives and reduced stripping risk. It’s a practical, high-performance choice for professional installers and serious DIYers tackling metal projects.

Pro tips for best results

• Use a compatible driver with a 1/4" hex washer head to maximize contact and drive efficiency.
• Keep the mating metal surfaces clean and aligned to ensure the threads engage smoothly from the first bite.
• Avoid over-tightening to protect the fastener’s clamping power and prevent panel distortion.