304 (A2) · 316 (A4) · 410 Stainless · C1022 Hardened · Mild Steel
Self Tapping Screws
Self-tappers that cut their own thread into sheet metal, plastic and timber, for brackets, panels and enclosures.
About the Self Tapping Screws
Self tapping screws, or self-tappers, cut their own thread into a pilot hole in sheet metal, plastic and timber, for brackets, panels, enclosures, ducting and caravan and trailer fit-out. They come with pan and countersunk heads and Phillips or square drive, zinc plated or black, or in 304, 316 and 410 stainless, from 2 to 14 gauge. Choose the head, finish and size above; the guide below covers sizes and choosing the right one.
Also called self-tappers or sheet metal screws.
Features
- Cuts its own thread, no tapping required
- Pan and countersunk (including undercut) heads
- Phillips and square (Robertson) drives
- Pilot point (410) for alignment on assembly lines
- Zinc-plated and stainless finishes
Applications
- Sheet metal and light steel
- Plastics and castings
- Brackets, panels and enclosures
- General assembly
Self tapping screws or tek screws?
A self tapping screw forms its own thread as it is driven, so you do not need to tap the hole, but it does need a pilot hole first. A tek screw (self-drilling screw) has a drill point and makes its own hole as well. Use self-tappers for sheet metal, plastics, fittings and assembly work where a neat, controlled fixing matters; use tek screws for fast fixing into steel framing and roofing.
The zinc plated and black self tappers are Type AB to ANSI B18.6.4: a sharp point and spaced thread for thin sheet metal, plastics and timber.
Self tapping screw sizes
Self tappers are sized by gauge and threads per inch, with the length in inches. A #8-18 x 3/4 is an 8 gauge screw (4.2mm thread) with 18 threads per inch, 3/4 inch (19mm) long.
Gauge, threads per inch and thread diameter.
| Gauge | Threads per inch | Thread diameter |
|---|---|---|
| #6 | 20 | 3.5mm |
| #8 | 18 | 4.2mm |
| #10 | 16 | 4.8mm |
| #12 | 14 | 5.5mm |
| #14 | 14 | 6.3mm |
Inch lengths in millimetres
Pan heads are measured from under the head; countersunk heads from the top of the head.
| Inches | mm | Inches | mm |
|---|---|---|---|
| 1/4 | 6.4 | 1 | 25.4 |
| 3/8 | 9.5 | 1-1/4 | 31.8 |
| 1/2 | 12.7 | 1-1/2 | 38.1 |
| 5/8 | 15.9 | 1-3/4 | 44.5 |
| 3/4 | 19.1 | 2 | 50.8 |
| 3 | 76.2 |
Heads, drives and finishes
- Pan head: a rounded head that sits on the surface, for fixing sheet, fittings and brackets.
- Countersunk head: sits flush in a countersunk hole.
- Phillips or square (Robertson) drive: square drive holds the bit firmly and is less likely to cam out.
- Zinc plated: for dry, indoor and low corrosion work.
- Zinc black passivate: a black finish for where the screw is on show.
- 304 stainless: for outdoor and wet work. 316 stainless for coastal and marine conditions.
- 410 stainless pilot point: a pilot point that fits a pre-drilled hole, speeding up alignment on assembly lines and in precision fabrication.
How to fix a self tapping screw
- Drill a pilot hole through the material, a little smaller than the screw thread.
- Drive the screw in straight with the correct bit, at a steady speed.
- Stop as soon as the head is seated. Overtightening strips the thread in thin sheet and plastic.
- In stainless, use stainless screws to avoid corrosion where metals meet.
Self tapping screws in Adelaide
Allmat supplies self tapping screws, tek screws and fixings to builders, fabricators and trade across Adelaide and South Australia. Add the screws you need to a quote with the rest of your list, and we will price the lot.
Self tapping screws for trade and workshop
Self tapping screws in every common gauge, length and finish are available to order from Allmat for builders, fabricators, electricians and trade across Adelaide and South Australia. Order through Allmat, we pick and pack it, then click and collect from the Allmat yard or have it delivered to site.
Goes with
Questions
What is the difference between a self tapping screw and a tek screw?
A self tapping screw cuts its own thread but needs a pilot hole. A tek screw has a drill point that makes its own hole and thread in one action.
Do self tapping screws need a pilot hole?
Yes. Drill a pilot hole a little smaller than the thread, then drive the screw. If you do not want to drill first, use a tek (self-drilling) screw.
What size is a #8 self tapping screw?
A #8 has a 4.2mm thread. A #6 is 3.5mm, #10 is 4.8mm, #12 is 5.5mm and #14 is 6.3mm.
What does #10-16 mean?
10 is the gauge (4.8mm thread) and 16 is the number of threads per inch.
Should I use 304 or 316 stainless self tappers?
304 for general outdoor and wet work, 316 near the coast and in marine conditions.
Where can I buy self tapping screws in Adelaide?
Order through Allmat. We supply self tapping screws in zinc, black and stainless to trade across Adelaide. Order ahead by phone on 1300 03 03 63 or send your list for a quote, then click and collect from 25 Kapara Road, Gillman, or have them delivered to site.
Self Tapping Screws: sizes and finishes we supply
615 lines by type and finish. Pick one above for its product code and pack sizes.
| Head | Finish | Sizes | Lengths | Lines |
|---|---|---|---|---|
| Countersunk | 304 Stainless | #4, #6, #6-20, #8, #8-18, #10, #10-16, #12, #12-14, #14 | 3/8 to 3 inch (11 lengths) | 96 |
| Pan | 304 Stainless | #4, #6, #6-20, #8, #8-18, #10, #10-16, #12, #14 | 1/4 to 3 inch (12 lengths) | 92 |
| Countersunk | Zinc Plated | #4-24, #5-20, #6-20, #8-18, #10-16, #12-14, #14-14 | 1/4 to 3 inch (12 lengths) | 85 |
| Countersunk | Zinc Black Passivate | #4-24, #5-20, #6-20, #8-18, #10-16, #12-14, #14-14 | 1/4 to 3 inch (12 lengths) | 84 |
| Pan | Zinc Black Passivate | #2-32, #4-24, #6-20, #8-18, #10-16, #12-14, #14-14 | 1/4 to 3 inch (12 lengths) | 83 |
| Pan | Zinc Plated | #2-32, #4-24, #6-20, #8-18, #10-16, #12-14, #14-14 | 1/4 to 3 inch (12 lengths) | 83 |
| Countersunk | 316 Stainless | #4, #6, #8, #10, #12, #14 | 1/4 to 2-1/2 inch (11 lengths) | 40 |
| Pan | 316 Stainless | #4, #6, #8, #10, #12, #14 | 1/4 to 3 inch (11 lengths) | 40 |
| Pan | 410 Stainless | #6, #8, #10 | 3/4, 1, 1-1/4, 1-1/2, 1-3/4, 2 inch | 10 |
| Pan | Zinc Plated | 6-12G | 9-50MM | 1 |
| Countersunk | 410 Stainless | #10-16 | 1/2 inch | 1 |
Data sheets and documents
The documents for the product you choose are listed with the selector above. Here is every Self Tapping Screws document from Hobson Engineering.
All Self Tapping Screws documents (10)
Data sheets and technical data (2)
Did You Know flyers (5)
Need them in bulk?
Add the sizes you need to your quote, or send us your list and we’ll price the lot and supply it with the rest of your order.
Browse all self-tapping screws