Quick answer: what replaces DIN 915?
ISO 4028 is the current successor for DIN 915 headless hexagon-socket set screws with dog point. DIN 915:1980-12 is withdrawn, but it remains a common designation on legacy drawings, replacement parts and commercial catalogues. The current standards chain is:
DIN 915:1980-12 → DIN EN ISO 4028:2004-05 → DIN EN ISO 4028:2026-06 / ISO 4028:2026
The cylindrical dog point is the defining feature. A replacement must preserve this locating geometry and be checked against the thread, length, socket, point dimensions, material, hardness, coating, mating feature and applicable edition.
DIN 915 cross-reference at a glance
| Standard | Product or scope | Replacement guidance |
|---|---|---|
| DIN 915:1980-12 | Hexagon socket set screw with dog point | Withdrawn legacy DIN reference |
| ISO 4028:2026 | Metric coarse-thread set screw with dog point | Primary current international reference |
| DIN EN ISO 4028:2026-06 | German adoption of current ISO 4028 | Preferred current DIN/EN/ISO reference |
| UNI 5925 | Italian dog-point hexagon socket set screw | Established national cross-reference; verify the cited edition |
| JIS B 1177 (T4) | Japanese dog-point configuration | Specify T4 and compare the controlled edition |
| ASME B18.3.6M, half-dog point | Corresponding US metric configuration | Verify point dimensions and edition; do not assume direct identity |
These references identify corresponding product families. They do not prove that every part is dimensionally or functionally interchangeable.
How the dog point works
A dog point is a reduced-diameter cylindrical projection at the end of the set screw. It is designed to enter a prepared hole, groove, recess or other locating feature in the mating part. In that arrangement it works more like a small locating pin than a friction-only set screw and can provide repeatable positioning and positive resistance to rotation or axial movement.
The mating feature is essential. Unlike a cone point, the dog point is not intended to form its own seat by penetrating a plain shaft. On an ungrooved surface it loses its main locating advantage and may bottom or contact incorrectly. If the shaft cannot be machined, a flat or cone point may be more practical after engineering review.
View the DIN 915 drawing and dimensions, or compare the related DIN 914 / ISO 4027 cone-point standard.
Current status, size range and thread scope
ISO 4028:2003 and DIN EN ISO 4028:2004-05 are withdrawn. The current references are ISO 4028:2026 and DIN EN ISO 4028:2026-06. ISO 4028:2026 specifies metric coarse-pitch threads, product grade A, with a current range of M1.6–M30 for steel and M1.6–M24 for stainless steel.
The larger steel range is not proof that every historical DIN 915 size or old drawing is identical to the 2026 product. Preserve any explicitly stated pitch, point dimension and edition. Do not silently convert a drawing-controlled fine pitch or special dog point into an unqualified coarse-thread ISO item.
What must match before substitution?
| Check | Why it matters |
|---|---|
| Thread diameter, pitch and tolerance | Determines assembly and thread engagement |
| Nominal length and length tolerance | Controls installed position and available engagement |
| Hexagon socket size and depth | Affect tool fit and torque transfer |
| Dog-point diameter and length | Must suit the mating hole, groove or recess |
| Threaded-body and point transition | Affects clearance and whether the screw bottoms correctly |
| Material and hardness class | Affect socket, point and thread deformation |
| Coating and lubrication | Affect corrosion, fit, friction and installation torque |
| Standard edition | Defines the dimensional and acceptance requirements |
An M8 × 20 callout alone is insufficient: the point type and point dimensions remain part of the functional interface. Check the actual mating feature, not only the fastener catalogue row.
Dog point is not automatically half dog
ASME B18.3.6M includes a corresponding metric half-dog-point configuration. It should not be described as an automatic dimension-for-dimension replacement for DIN 915 / ISO 4028. Compare point length and diameter, overall length convention, socket, thread, tolerances, material requirements and the selected edition.
For the Japanese reference, use JIS B 1177 (T4) rather than the unqualified family number, because JIS B 1177 contains multiple point configurations. The dog-point type and its controlled dimensions must be stated.
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 surface contact without a locating projection |
| ISO 4027 | DIN 914 | Truncated cone point | Concentrated contact or engagement in 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 the mating surface |
Matching diameter and length do not make these point forms equivalent. Changing the point can alter clearance, surface damage, positioning accuracy and resistance to rotation or axial movement.
Hardness, material, loading and temperature
DIN 915 / ISO 4028 set screws use the mechanical-property framework for set screws, not ordinary bolt property classes such as 8.8, 10.9 or 12.9. A hardened-steel product is 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. Dog-point engagement may resist movement of the mating part, but capacity depends on the point, mating feature, material, tightening condition and complete joint design. ISO 4028 also gives no universal operating-temperature rating; temperature capability follows from the actual material, heat treatment, coating, lubrication and application.
Selection and installation checklist
For a controlled replacement or purchase order, specify:
- ISO 4028 or DIN EN ISO 4028 and the required edition
- Dog-point configuration, not merely “hexagon socket set screw”
- Thread diameter, pitch, tolerance and nominal length
- Dog-point diameter and length when fit is critical
- Mating-hole, groove or recess diameter, depth and alignment
- Socket dimensions when drawing-controlled
- Steel hardness class or stainless-steel grade
- Coating, lubrication, inspection and approval requirements
Confirm that the cylindrical point enters the locating feature without bottoming on an unintended surface and that sufficient thread engagement remains. Use the correct undamaged hex key with full socket engagement. For safety-critical retention, verify the assembled joint rather than assigning a universal holding value to DIN 915 or ISO 4028.