Product Description
No.4 A2 Stainless Steel Raised Countersunk Slotted Self Tapping Screws
These No.4 raised countersunk self tapping screws are manufactured from A2 stainless steel and feature a traditional slotted drive. The raised countersunk, also known as oval, head provides a neat finished appearance while allowing most of the head to sit within a suitable countersunk recess.
The self tapping thread is designed to form a mating thread during installation into a correctly sized pilot hole. No.4 self tapping screws correspond to the metric thread designation ST2.9.
Product Features
- No.4 / ST2.9 self tapping thread
- A2 stainless steel construction
- Raised countersunk oval head
- Traditional slotted drive
- Approximately 5.2mm head diameter
- Suitable for general indoor and outdoor applications
- Available in lengths from 3/8" to 1 1/4"
- Legacy dimensional standard: DIN 7973
- Current dimensional standard: ISO 1483 / BS EN ISO 1483
Standards Information
DIN 7973 is the legacy standard commonly associated with slotted raised countersunk head self tapping screws. The current dimensional standard is ISO 1483:2011, adopted in Britain as BS EN ISO 1483:2011.
ISO 1483 covers slotted raised countersunk, or oval head, tapping screws with thread designations from ST2.2 to ST9.5. The No.4 / ST2.9 size falls within this dimensional range.
A2 stainless steel provides good general corrosion resistance for indoor, outdoor and damp applications. For prolonged exposure to saltwater, swimming-pool environments or aggressive chemicals, A4 stainless steel may be more suitable.
Installation Guidance
Select a pilot-hole diameter suitable for the substrate thickness and application. Stainless steel self tapping screws should not be forced into an undersized pilot hole or excessively hard material, as this may damage the thread or cause the screw to fail.
Use a correctly fitting flat-blade screwdriver and apply steady pressure during installation. Avoid excessive installation speed and overtightening.
Please note: Specifications are provided as a guide. If any dimension or standard is critical to your application, please contact us before ordering.
| A | B | C | D | E | F |
| No.4 | 2.9mm | 1 1/4" | 32mm | 33/64" | 5.2mm |
| No.4 | 2.9mm | 1" | 25mm | 33/64" | 5.2mm |
| No.4 | 2.9mm | 1/2" | 13mm | 33/64" | 5.2mm |
| No.4 | 2.9mm | 3/4" | 19mm | 33/64" | 5.2mm |
| No.4 | 2.9mm | 3/8" | 9.5mm | 33/64" | 5.2mm |
| No.4 | 2.9mm | 5/8" | 16mm | 33/64" | 5.2mm |
Please Note: Specifications given are intended as a guide only. If critical to your project please check with us first.
