Self Tapping Screws for Metal: A Practical Guide

What Are Self Tapping Screws for Metal?

Self tapping screws are designed to form their own thread as they’re driven into metal. Unlike self drilling screws, these fixings require a pre-drilled pilot hole. Once in place, the screw cuts a clean thread into the metal, providing a secure fixing without the need for tapping.

All self tapping screws in our range feature:

• An AB point
• A 60° self tapping thread

Controlled, accurate thread formation in metal

They’re ideal for light to medium metal sections, sheet steel, brackets and box section.

Where Are Self Tapping Screws Commonly Used?

Self tapping screws for metal are widely used in:

• Sheet metal fabrication
• Electrical containment and trunking
• HVAC and ducting
• Metal framing and brackets
• General construction and maintenance

Because a pilot hole is used, they offer better control and reduce the risk of snapping – particularly when working with stainless steel.

Types of Self Tapping Screws for Metal

Rather than cutting or drilling methods, the main difference between self tapping screws in this range is head type. The correct head style affects both appearance and clamping strength.

Countersunk Self Tapping Screws

Countersunk self tapping screws are designed to sit flush with the metal surface once installed.

Best used when:

• A neat, flush finish is required
• Fixings are visible
• Panels or plates need to sit flat

Available in:

• Zinc plated (CR3) for internal use
• Stainless steel for outdoor or damp environments

Pan Head Self Tapping Screws

Pan head self tapping screws have a raised head with a wider bearing surface, providing extra clamping force.

Best used when:

• Strength is more important than appearance
• Fixing thinner metals together
• Additional load spread is needed

Available in:

• Zinc plated (CR3)
• Stainless steel

Flange Head Self Tapping Screws

Flange head self tapping screws feature an integrated washer under the head, helping to spread the load.

Best used when:

• Working with thin sheet metal
• Extra coverage is needed under the head
• You want to avoid using separate washers

Available in:

• Zinc plated (CR3)
• Stainless steel

Zinc vs Stainless Steel: Which Should You Use?

Choosing the right material depends on the environment.

Zinc Plated (CR3)

• Suitable for dry, internal applications
• Cost-effective for general use
• Trivalent Chromium plating, 3 microns

Stainless Steel

• Suitable for external use and damp conditions
• Better corrosion resistance
• Requires slower driving speeds to prevent snapping

Using Self Tapping Screws Correctly

For best results when fixing into metal:

• Drill a correctly sized pilot hole
• Use the correct driver bit to prevent cam-out
• Apply steady pressure – don’t force the screw
• Avoid over-tightening, which can strip threads

When installing stainless steel screws, slower speeds reduce heat build-up and help prevent failure.

Frequently Asked Questions

Do self tapping screws for metal require a pilot hole?
Yes. A pilot hole is required to allow the AB point to form the thread correctly in metal.

Can these screws be used for metal to metal fixing?
Yes. They’re designed specifically for stitching metal to metal, including sheet steel and light sections.

Are stainless steel self tapping screws harder to install?
Stainless steel is harder than zinc plated steel, so slower speeds and steady pressure are recommended to reduce the risk of snapping.

What head type should I choose?

• Countersunk for a flush finish
• Pan head for extra clamping strength
• Flange head for load spread without washers

What’s included in the mixed tray?
The mixed tray includes pan, countersunk and flange head self tapping screws in multiple sizes, ideal for general trade use.