Description
Overview
DIN 933 defines a hexagon head set screw with a fully threaded shank. The standard covers the dimensional form of the head, thread and length so the fastener can be selected consistently by diameter, thread and overall length. The fully threaded design is useful where thread engagement is required along the full length of the fastener, or where the screw is installed into a tapped hole rather than used with a nut.
This selected size is specified with diameter M20, length 90 mm, thread M20, pitch 2.5 mm.
Sold in multiples of '10 pieces. 1 Box = '10 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 anti-seize may be required.
Finish & Corrosion Protection
The finish should be matched to the environment, appearance requirements and expected corrosion exposure.
Typical Uses
DIN 933 set screws are commonly used in machinery, fabricated steelwork, brackets, frames, maintenance work and general engineering where a fully threaded hexagon head fastener is preferred.
Technical Tips
- Use DIN 933 where full thread engagement is required.
- For bolted joints, use a matching nut and washer of the same thread size and suitable strength class.
- For Grade 8.8, 10.9 or 12.9 parts, use correctly rated mating nuts and washers.
- Torque values vary by diameter, pitch, finish and lubrication; confirm the correct torque for critical assemblies.
Selection Advice
Choose DIN 933 when a fully threaded hexagon head fastener is required. Choose DIN 931 when the joint benefits from a partially threaded plain shank for alignment or shear loading.
Frequently Asked Questions
What is the difference between DIN 933 and DIN 931? DIN 933 is fully threaded, while DIN 931 is partially threaded. DIN 933 is often preferred for tapped holes or applications where the full length must provide thread engagement.
Dimensions – DIN 933 / ISO 4017 M20 x 90
| Standard | DIN 933 / ISO 4017 |
|---|---|
| Product | Hexagon head set screw, full thread |
| Thread | M20 x 2.5 |
| Length (l) | 90 mm |
| Across flats (s) | 30 mm |
| Head height (k) | 13 mm |
| Thread length (b) | full thread |
| Stress area (As) | 244.8 mm² |
| Weight (calculated) | 268.51 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 933 data sheet – all sizes
| Size | Thread | Across flats (s) | Head height (k) | Thread length (b) | Stress area (As) |
|---|---|---|---|---|---|
| M3 | M3 x 0.5 | 5.5 mm | 2 mm | full thread | 5.0 mm² |
| M4 | M4 x 0.7 | 7 mm | 2.8 mm | full thread | 8.8 mm² |
| M5 | M5 x 0.8 | 8 mm | 3.5 mm | full thread | 14.2 mm² |
| M6 | M6 x 1 | 10 mm | 4 mm | full thread | 20.1 mm² |
| M7 | M7 x 1 | 11 mm | 4.8 mm | full thread | 28.9 mm² |
| M8 | M8 x 1.25 | 13 mm | 5.5 mm | full thread | 36.6 mm² |
| M10 | M10 x 1.5 | 17 mm (ISO: 16 mm) | 7 mm | full thread | 58.0 mm² |
| M12 | M12 x 1.75 | 19 mm (ISO: 18 mm) | 8 mm | full thread | 84.3 mm² |
| M14 | M14 x 2 | 22 mm (ISO: 21 mm) | 9 mm | full thread | 115.4 mm² |
| M16 | M16 x 2 | 24 mm | 10 mm | full thread | 156.7 mm² |
| M18 | M18 x 2.5 | 27 mm | 12 mm | full thread | 192.5 mm² |
| M20 | M20 x 2.5 | 30 mm | 13 mm | full thread | 244.8 mm² |
| M22 | M22 x 2.5 | 32 mm (ISO: 34 mm) | 14 mm | full thread | 303.4 mm² |
| M24 | M24 x 3 | 36 mm | 15 mm | full thread | 352.5 mm² |
| M27 | M27 x 3 | 41 mm | 17 mm | full thread | 459.4 mm² |
| M30 | M30 x 3.5 | 46 mm | 19 mm | full thread | 560.6 mm² |
| M33 | M33 x 3.5 | 50 mm | 21 mm | full thread | 693.6 mm² |
| M36 | M36 x 4 | 55 mm | 23 mm | full thread | 816.7 mm² |
| M39 | M39 x 4 | 60 mm | 25 mm | full thread | 975.8 mm² |
| M42 | M42 x 4.5 | 65 mm | 26 mm | full thread | 1120.9 mm² |
| M45 | M45 x 4.5 | 70 mm | 28 mm | full thread | 1306.0 mm² |
| M48 | M48 x 5 | 75 mm | 30 mm | full thread | 1473.1 mm² |
| M52 | M52 x 5 | 80 mm | 33 mm | full thread | 1757.8 mm² |
| M56 | M56 x 5.5 | 85 mm | 35 mm | full thread | 2030.0 mm² |
| M60 | M60 x 5.5 | 90 mm | 38 mm | full thread | 2362.0 mm² |
| M64 | M64 x 6 | 95 mm | 40 mm | full thread | 2676.0 mm² |
Nominal dimensions per DIN 933 / ISO 4017. 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 | M20 |
| Thread Pitch | 2.5 mm |
| Thread Style | Fully Thread |
| Drive Size | 30 mm |
| Drive Type | External Hex |
| Head Style | Hex |
| Diameter | M20 |
| Length | 90 mm |
| Material | Stainless Steel |
| Finish | Stainless steel |
| Grade | Grade (A2) |
| Standards Met | DIN 933 |
| Package Quantity | 10 |
| Package Type | Box |