Description
Overview
DIN 963 defines a slotted countersunk machine screw with a flat head designed to sit flush in a countersunk hole. The standard controls the head angle, slot form, thread and dimensional proportions so the screw can be used consistently in light mechanical and panel assemblies.
This selected size is specified with diameter M8, length 20 mm, thread M8, pitch 1.25 mm.
Sold in multiples of '100 pieces. 1 Box = '100 pieces.
Material, Grade & Strength
A2 stainless steel, commonly associated with 304 stainless, provides good general corrosion resistance for outdoor, clean industrial and food-related environments. Stainless threads can gall, so suitable anti-seize may be required.
Finish & Corrosion Protection
Corrosion resistance is provided by the stainless material itself rather than a plated coating.
Typical Uses
DIN 963 countersunk slotted machine screws are used in panels, covers, electrical assemblies, light engineering, fixtures and applications where a flush surface is required with a simple flat screwdriver drive.
Technical Tips
- Use a correctly formed countersink so the head seats evenly and does not stand proud.
- Avoid over-tightening slotted screws as the drive can cam out or damage the slot.
- Use with a tapped hole or matching nut of the same thread size.
- Choose stainless steel where corrosion resistance is required.
Frequently Asked Questions
When should a countersunk screw be used? Use countersunk screws where the head must sit flush with the surface or where a protruding head would interfere with movement or appearance.
Dimensions – DIN 963 / ISO 2009 M8 x 20
| Standard | DIN 963 / ISO 2009 |
|---|---|
| Product | Slotted countersunk machine screw |
| Thread | M8 x 1.25 |
| Length (l) | 20 mm (overall) |
| Head diameter (dk) | 14.5 mm |
| Head height (k) | 4 mm |
| Drive | Slotted |
| Weight (calculated) | 8.35 kg per 1 000 pieces |
Material, Grade & Strength
| Material | Stainless steel A2 (304) |
|---|---|
| Steel grade | AISI 304 (1.4301) |
| Composition | C max 0.07%, Cr 17.5-19.5%, Ni 8.0-10.5% |
| Property class | A2-70 (ISO 3506) unless marked -80 |
| Tensile strength Rm (min) | 700 MPa (class 70), 800 MPa (class 80) |
| Yield Rp0.2 (min) | 450 MPa (class 70), 600 MPa (class 80) |
| Typical use | general corrosion resistance, indoor/outdoor, food equipment |
Finish & Corrosion Protection
Plain / self colour: No applied coating. Stainless, brass and nylon parts are supplied plain; plain steel parts need oil, paint or protected environments.
DIN 963 data sheet – all sizes
| Size | Thread | Head diameter (dk) | Head height (k) | Drive |
|---|---|---|---|---|
| M2 | M2 x 0.4 | 3.8 mm | 1.2 mm | Slotted |
| M2.5 | M2.5 x 0.45 | 4.7 mm | 1.5 mm | Slotted |
| M3 | M3 x 0.5 | 5.6 mm | 1.65 mm | Slotted |
| M3.5 | M3.5 x 0.6 | 6.5 mm | 1.93 mm | Slotted |
| M4 | M4 x 0.7 | 7.5 mm | 2.2 mm | Slotted |
| M5 | M5 x 0.8 | 9.2 mm | 2.5 mm | Slotted |
| M6 | M6 x 1 | 11 mm | 3 mm | Slotted |
| M8 | M8 x 1.25 | 14.5 mm | 4 mm | Slotted |
| M10 | M10 x 1.5 | 18 mm | 5 mm | Slotted |
Nominal dimensions per DIN 963 / ISO 2009. Weights are calculated from nominal dimensions and are a guide only (±10%). Values for fit and strength should be confirmed against the standard for critical applications.
Specifications
| Measurement Type | Metric |
|---|---|
| Thread Size | M8 |
| Thread Pitch | 1.25 mm |
| Thread Style | Fully Thread |
| Drive Type | Slotted |
| Head Style | Countersunk |
| Diameter | M8 |
| Length | 20 mm |
| Material | Stainless Steel |
| Finish | Stainless steel |
| Grade | Grade (A2) |
| Standards Met | DIN 963 |
| Package Quantity | 100 |
| Package Type | Box |