About Tapping Screws
While other screws and bolts require holes with threads, tapping screws create their own threads.
Pointed screws are the most common tapping screw. They have a pointed end to penetrate thin material such as sheet metal, and soft material such as wood and drywall. In thicker material, they generally need a starter hole.
Thread-forming and thread-cutting screws create reusable threads in metals and plastics. They require a drilled or punched hole to install. Thread-forming screws press threads into material for a tight, vibration resistant assembly, while thread-cutting screws require less driving torque and cause less stress on material than thread-forming screws.
Drilling screws save you time and effort by drilling their own holes, creating reusable threads, and fastening material in a single operation.
Material
316 Stainless Steel—Our most corrosion resistant stainless steel, it has excellent resistance to chemicals and salt water and may be mildly magnetic.
18-8 Stainless Steel—Has good chemical resistance and may be mildly magnetic.
410 Stainless Steel—Stronger and more wear resistant than 316 and 18-8 stainless steel, it is mildly chemical resistant and magnetic. Not for use with aluminum.
Brass—Corrosion resistant in wet environments, electrically conductive, and nonmagnetic.
Aluminum—One-third the weight of steel, aluminum resists corrosion in wet environments and is nonmagnetic.
Steel—This general purpose metal is often plated with zinc for corrosion resistance in wet environments.
Finish
Zinc Plated and Black Zinc-Plated—Provide corrosion resistance in wet environments.
Black Oxide and Black Phosphate—Offer corrosion resistance in dry environments.
Black Ultra-Corrosion-Resistant Coated—More corrosion resistant than zinc plating and provides a decorative finish that won’t rub off.
Chrome Plated—Bright and attractive. Offers corrosion resistance in wet environments.
Nickel Plated—A decorative finish that’s more corrosion resistant than zinc plating and less expensive than chrome plating.
Ultra-Corrosion-Resistant Coated—Resists corrosion better than zinc plating and minimizes reactions between dissimilar metals.
How to Read a Screw Size
The screw size listed for thread-forming, thread-cutting, and drilling screws is the size of the threads they create.
