How to Install Self-Drilling TEK Screws into Metal

By Mutual Screw & Supply | Published: 2026-10-21

Category: How-to Guides

Learn the correct steps for installing self-drilling TEK screws into metal, including drill speed, pressure, and common mistakes to avoid for a secure fastening.

Quick Answer

Use a variable-speed drill at a medium RPM, apply steady pressure, and let the screw's self-drilling tip do the work. Avoid pushing too hard or using excessive speed, which can strip the screw or damage the metal.

Why Self-Drilling TEK Screws Work Differently

Unlike self-tapping screws that require a pre-drilled pilot hole, self-drilling TEK screws have a drill bit tip that cuts through metal as you drive them. This saves time and eliminates the need for a separate drilling step. However, the technique matters: using the wrong drill speed or applying too much pressure can dull the tip or cause the screw to spin without cutting.

When to Use Hex Washer Head TEK Screws

The hex washer head design, common on TEK screws like the #10 X 1-1/2" Self-Drilling Screws from Mutual Screw & Supply, provides a larger bearing surface that distributes clamping force and protects the material surface. This makes them ideal for metal roofing, siding, and framing where a flush, secure fit is needed. For softer metals or thin gauge, a hex washer head helps prevent pull-through.

Step-by-Step Installation Guide

Step 1: Select the Right Screw Length and Drill Speed: Choose a screw long enough to penetrate both layers of metal with at least 1/4" of thread engagement. For most metal thicknesses up to 1/8", use a variable-speed drill set to medium RPM (around 1500-2000). Thicker metal may require slower speed to avoid overheating the tip. Common mistake: Using a high-speed drill can overheat the self-drilling tip, causing it to lose hardness and fail to cut.
Step 2: Align and Start the Screw Perpendicular: Place the screw tip squarely against the metal surface at a 90-degree angle. Apply light pressure to engage the drill bit tip. Let the screw drill its own pilot hole before applying full driving force. Checkpoint: If the screw wanders or skips, stop and reposition. Starting at an angle can cause the screw to bend or snap.
Step 3: Drive Until the Washer Contacts the Surface: Once the tip penetrates, increase pressure slightly and drive the screw until the hex washer head just contacts the metal. Do not overtighten—this can strip the threads or dimple the metal. For thin gauge, stop as soon as the washer touches. Common mistake: Overdriving can compress the washer too much, reducing its sealing ability and potentially cracking the material.

Product Facts

#10 X 1-1/2" Self-Drilling (TEK) Screws | Hex Washer Head | Steel Zinc Plated (100 / Pkg.): These #10 self-drilling screws are made from steel with a zinc plated finish and feature a hex head. The zinc plating provides corrosion resistance for outdoor or damp environments, while the hex head allows for a secure grip with a socket or drill driver.
#10 X 1-1/2" Self-Drilling (TEK) Screws | Hex Washer Head | Steel Zinc Plated (100 / Pkg.)