Quick answer: what replaces DIN 916?
ISO 4029 is the current successor for DIN 916 headless hexagon-socket set screws with cup point. DIN 916 is a legacy German designation that remains common on drawings, replacement parts and commercial catalogues. The current standards path is:
DIN 916 → DIN EN ISO 4029 → ISO 4029:2026
ISO 4029:2003 is withdrawn. A current ISO number does not by itself approve a replacement: verify the thread, length, socket, cup-point geometry, material, hardness, coating, mating surface and applicable edition.
DIN 916 cross-reference at a glance
| Standard | Product or scope | Replacement guidance |
|---|---|---|
| DIN 916 | Hexagon socket set screw with cup point | Legacy DIN drawing and trade reference |
| ISO 4029:2026 | Metric coarse-thread set screw with cup point | Primary current international reference |
| DIN EN ISO 4029:2026 | Current German adoption of ISO 4029 | Preferred current DIN/EN/ISO reference |
| UNI 5929 | Italian cup-point hexagon socket set screw | Corresponding national family; verify the cited edition |
| JIS B 1177, cup-point type | Japanese set-screw family with multiple point types | Specify the cup-point configuration and controlled edition |
| ASME B18.3.6M | Historical metric socket set-screw reference | Verify the cup-point table and dimensions; do not present it as a current one-to-one equivalent |
These references identify corresponding product families. They do not prove that every item is dimensionally and functionally interchangeable.
How the cup point works
The cup point has a concave end whose circular rim bites into the mating surface as the screw is tightened. This produces localized gripping contact for retaining hubs, collars, gears or pulleys and resisting relative movement. Unlike a DIN 915 / ISO 4028 dog point, it normally does not require a pre-machined hole or groove.
That convenience has a trade-off: the rim normally marks or indents the shaft. The actual holding behaviour depends on screw size, tightening condition, point geometry, shaft material, surface hardness, coating and the complete joint. DIN 916 or ISO 4029 does not provide one universal holding-load value.
For a finished shaft, a fatigue-sensitive surface or a component that will be repositioned frequently, a DIN 913 / ISO 4026 flat point may be more suitable after engineering review. View the DIN 916 drawing and dimensions, or compare the related DIN 915 / ISO 4028 dog-point standard.
Current status, size range and thread scope
ISO 4029:2003 is withdrawn and replaced by ISO 4029:2026. The current edition specifies metric coarse-pitch threads, product grade A, with a range of M1.6–M30 for steel and M1.6–M24 for stainless steel.
The larger current steel range does not make every historical DIN 916 item identical to a 2026 product. Preserve any explicit pitch, length, point geometry and edition on a controlled drawing. Do not infer that a special or legacy thread is covered merely because the nominal diameter appears in a current catalogue.
What must match before substitution?
| Check | Why it matters |
|---|---|
| Thread diameter, pitch and tolerance | Determine assembly and thread engagement |
| Nominal length and tolerance | Control installed depth and point position |
| Hexagon socket size and depth | Affect tool fit and torque transfer |
| Cup diameter, depth and rim geometry | Determine contact, penetration and surface marking |
| Material and hardness class | Affect socket, point and thread deformation |
| Mating-surface material and hardness | Strongly influence indentation and holding behaviour |
| Coating and lubrication | Affect corrosion, fit, friction and installation torque |
| Standard edition | Defines dimensions and acceptance requirements |
An M10 × 20 description alone is incomplete. It must also identify the cup point and the applicable material or hardness requirements.
ASME, JIS and serrated cup points need qualification
ASME B18.3.6M is a historical metric socket set-screw reference, not a current automatic equivalent of ISO 4029:2026. Confirm that the selected ASME table actually covers cup point, then compare thread, length convention, socket, point dimensions, tolerances, material requirements and edition.
JIS B 1177 covers more than one point configuration, so specify the cup-point type rather than only the family number. An ordinary ISO 4029 cup point must also not be confused with a serrated or knurled cup point. If a drawing requires serrations, verify the governing product specification and exact point geometry separately.
Do not confuse the four set-screw point families
| Current ISO | Legacy DIN | Point form | Typical selection reason |
|---|---|---|---|
| ISO 4026 | DIN 913 | Flat point | Broad contact and less aggressive marking |
| ISO 4027 | DIN 914 | Truncated cone point | Concentrated contact or a prepared dimple |
| ISO 4028 | DIN 915 | Dog point | Positive location in a matching hole, groove or recess |
| ISO 4029 | DIN 916 | Cup point | Rim contact that bites into an unmachined mating surface |
These point forms use different contact mechanisms. There is no universal holding-strength ranking that applies to every shaft material, tightening condition and joint. Changing the point requires an application review even when thread and length match.
Hardness, material, loading and temperature
DIN 916 / ISO 4029 set screws use the mechanical-property framework for set screws, not ordinary bolt property classes such as 8.8, 10.9 or 12.9. Hardened-steel products are often supplied as 45H, but 45H is not the same designation as 12.9 and is not automatic for every product. Specify the required hardness class or stainless-steel grade using the applicable requirements, such as ISO 898-5 or ISO 3506-3.
Set screws are not intended to serve as tensile-loaded bolts. Their function is local gripping or retention through the point and joint interface. ISO 4029 also gives no universal operating-temperature rating; temperature capability follows from the actual material, heat treatment, coating, lubrication, mating part and environment.
Selection and installation checklist
For a controlled replacement or purchase order, specify:
- ISO 4029 or DIN EN ISO 4029 and the required edition
- Ordinary cup point, or a separately defined serrated point if required
- Thread diameter, pitch, tolerance and nominal length
- Socket and cup-point dimensions when drawing-critical
- Steel hardness class or stainless-steel grade
- Mating-surface material, hardness and acceptable marking
- Coating, lubrication and inspection requirements
- Approval for any change from a legacy DIN 916 drawing
Use the correct undamaged hex key with full socket engagement and do not compensate for poor seating with uncontrolled torque. Inspect the shaft surface and cup rim when repositioning or reusing a screw. For safety-critical retention, verify the assembled joint rather than assigning a universal holding value to DIN 916 or ISO 4029.