The DIN 913 stainless set screw is a headless metric fastener with an internal hex drive and flat point for positioning, adjustment, and frictional locking. DIN 913:1980-12 is withdrawn; its product form was replaced by DIN EN ISO 4026, whose current edition is DIN EN ISO 4026:2026-06 based on ISO 4026:2026. For stainless steel, the current standard covers metric coarse threads from M1.6 to M24, product grade A. Common market materials include A2 and A4 stainless steel.
Product Overview and Key Features
The screw is threaded over its body and can sit below or flush with the surrounding surface. Its flat end spreads contact over a broader area than penetrating point styles.
- Flat point: provides broad contact for clamping or adjustment without deliberately biting into the mating surface.
- Headless design: allows installation flush with or below the component surface.
- Internal hex drive: supports compact installation where an external wrenching head would interfere.
- Metric coarse thread: current stainless ISO 4026 coverage extends from M1.6 through M24.
- Stainless options: A2 and A4 are common catalog materials for different corrosion environments.
DIN 913 Stainless Set Screw Specifications
Specification Overview
| Item | Specification / Common Configuration |
|---|---|
| Legacy designation | DIN 913:1980-12, withdrawn |
| Current German standard | DIN EN ISO 4026:2026-06 |
| International standard | ISO 4026:2026 |
| Product form | Hexagon socket set screw with flat point |
| Stainless thread range | M1.6 to M24, metric coarse pitch |
| Product grade | A |
| Mechanical-property reference | ISO 3506-3:2025 for stainless set screws |
| Common stainless grades | A2 and A4 |
| Common hardness class | 21H is a widely cataloged stainless configuration; specify the required class in the RFQ |
| Current stainless surface options | Clean and bright or passivated, as specified |
Dimensions, Hex Socket and Common Lengths
The table summarizes selected ISO 4026 dimensions for the stainless range. P is coarse thread pitch, d1 is maximum flat-point diameter, s is nominal hex socket size, and t is minimum socket depth. Length examples are commercial combinations, not a continuous range for every diameter.
| Thread | P (mm) | Example Lengths (mm) | d1 Max (mm) | s Nom. (mm) | t Min. (mm) |
|---|---|---|---|---|---|
| M2.5 | 0.45 | 3, 5, 8, 10, 12 | 1.5 | 1.3 | 1.2 |
| M3 | 0.50 | 4, 5, 6, 8, 10, 12 | 2.0 | 1.5 | 1.2 |
| M4 | 0.70 | 4, 6, 8, 10, 12, 16 | 2.5 | 2.0 | 1.5 |
| M5 | 0.80 | 5, 8, 10, 12, 16, 20 | 3.5 | 2.5 | 2.0 |
| M6 | 1.00 | 6, 10, 12, 16, 20, 25 | 4.0 | 3.0 | 2.0 |
| M8 | 1.25 | 8, 12, 16, 20, 25, 30 | 5.5 | 4.0 | 3.0 |
| M10 | 1.50 | 10, 16, 20, 25, 30, 40 | 7.0 | 5.0 | 4.0 |
| M12 | 1.75 | 12, 20, 25, 30, 40, 50 | 8.5 | 6.0 | 4.8 |
| M16 | 2.00 | 16, 20, 25, 30, 40, 60 | 12.0 | 8.0 | 6.4 |
| M20 | 2.50 | 20, 25, 30, 35, 40, 60 | 15.0 | 10.0 | 8.0 |
The current stainless scope also includes M1.6, M2 and M24. New drawings should use the current ISO-based designation; replacement orders can retain DIN 913 when legacy geometry must be matched.
Common Stainless Grades and Surface Conditions
A2 and A4 Stainless Steel Options
A2 stainless is common for general machinery and mildly corrosive environments. A4 contains molybdenum and is commonly selected where chloride exposure warrants greater pitting resistance. A2-21H and A4-21H are established market configurations under the ISO 3506-3 hardness-class system.
Finish and Passivation Options
ISO 4026:2026 identifies clean-and-bright and passivated stainless surface conditions. Zinc plating is not normally required for A2 or A4 stainless. Confirm grade, hardness class, finish, thread, and length during quotation.
Typical Applications and Selection Considerations
- Shaft collars, hubs, stops, knobs, and adjustable machine components.
- Automation equipment, instruments, fixtures, and positioning mechanisms.
- Applications requiring repeated adjustment with less deliberate surface penetration than cone- or cup-point screws.
Flybear’s set screw point types guide compares flat, cup, cone, and dog points. Buyers can also compare the alloy-steel flat point set screw when corrosion resistance is not the primary requirement. Flat points can still mark soft surfaces, and ISO 4026 set screws are not intended for tensile loading.
Ordering and Quality Documentation
An RFQ should state DIN 913 for a legacy replacement or ISO 4026:2026 for a current product, together with size, length, stainless grade, hardness class, surface condition, quantity, and application. Buyers may request material verification, dimensional inspection, thread gauging, hardness, proof-torque, and passivation documentation. Flybear’s quality control and inspection page describes related inspection support; exact acceptance requirements should be agreed for each order.
Frequently Asked Questions
Is DIN 913 still a current standard?
No. DIN 913:1980-12 is withdrawn. It was replaced by DIN EN ISO 4026, and the current German edition is DIN EN ISO 4026:2026-06. DIN 913 remains common on legacy drawings and purchase records.
What stainless sizes are covered by current ISO 4026?
ISO 4026:2026 covers stainless steel flat-point hex socket set screws from M1.6 through M24 using metric coarse pitches and product grade A. M30 was added in 2026 for steel, not stainless.
What is the difference between A2 and A4 stainless?
A2 is a general-purpose austenitic stainless grade. A4 includes molybdenum and generally provides better pitting resistance in chloride-bearing environments. Select by exposure, temperature, and mating material.
Why choose a flat point instead of a cup point?
A flat point spreads contact over a broader surface and suits repeated adjustment or reduced penetration. A cup point concentrates contact around an edge and can provide more biting action but usually leaves a stronger mark.
What information should I provide for quotation?
Provide the standard, thread size, length, A2 or A4 grade, hardness class, surface condition, quantity, mating material, and application. Include a drawing for legacy dimensions, special lengths, or controlled geometry.
Request a Quote for DIN 913 Stainless Set Screws
Send Flybear Industrial your DIN 913 stainless set screw size, length, A2 or A4 grade, hardness class, surface condition, quantity, and application requirements. Include drawings for legacy or custom configurations. Submit the details through the Flybear fastener RFQ page for technical review and quotation.
