DIN 438 Slotted Set Screws with Cup Point
DIN 438 set screws with slotted head and cup point, M1.6 to M12 — the concave punch point that bites a small annulus into the opposing surface — with the full collected 10-size table: cup diameter, slot and engagement depth limits.
Last updated: 2026-11
Specifications
DIN 438 is the cup-point member of the slotted set screw family: the point is a shallow concave cup whose rim — not its centre — meets the mating surface. That rim bites into shafts and soft members with a small circular imprint, giving a repeatable, high-pressure grip that resists rotation without the deep dimple a cone point leaves or the groove a dog point demands. It is the default slotted set screw for locking collars, pulleys and handwheels onto shafts where a mark on the shaft is acceptable and a positive groove is not. The collected table runs M1.6 to M12 and tabulates per size: the cup diameter dz with its min / max=nominal limits (the rim diameter that sets the bite circle), the slot width n and slot depth t limits, and the pitch P. The slotted drive makes these screws the maintenance-friendly choice in exposed mechanisms where a hex key socket would pack with dust — and where a flat blade is always at hand. Materials, property classes and finishes are not printed by the collected specification and follow the drawing callout.
| Standard | DIN 438 — slotted set screws with cup point (concave rim point) |
|---|---|
| Series | M1.6 – M12 (10 sizes tabulated) |
| Tabulated geometry | Per size: pitch P, cup diameter dz (min / max=nominal), slot width n (max / min), slot depth t (min=nominal / max) |
| Dimensions at M3 | dz min 1.15 / max=nominal 1.4; n max 0.6 / min 0.46; t min 0.8 / max 1.05 |
| Dimensions at M6 | dz min 2.75 / max=nominal 3; n max 1.2 / min 1.06; t min 1.6 / max 2 |
| Dimensions at M12 | dz min 7.7 / max=nominal 8; n max 2.31 / min 2.06; t min 2.8 / max 3.6 |
| Point form | Cup point — concave rim bites a circular imprint into the mating surface for rotation lock |
| Materials / strength | Not tabulated by the collected specification — per RFQ (property class and finish per drawing callout) |
| d thread size | P | n nom | t min/max | dz min/max | ||
|---|---|---|---|---|---|---|
| M 1.6 | 0.35 | 0.25 | 0.56 | 0.74 | 0.55 | 0.8 |
| M 2 | 0.4 | 0.25 | 0.64 | 0.84 | 0.75 | 1 |
| M 2.5 | 0.45 | 0.4 | 0.71 | 0.96 | 0.95 | 1.2 |
| M 3 | 0.5 | 0.4 | 0.8 | 1.06 | 1.15 | 1.4 |
| M 3.5 | 0.6 | 0.5 | 0.96 | 1.21 | 1.45 | 1.7 |
| M 4 | 0.7 | 0.6 | 1.12 | 1.42 | 1.75 | 2 |
| M 5 | 0.8 | 0.8 | 1.28 | 1.63 | 2.25 | 2.5 |
| M 6 | 1 | 1 | 1.6 | 2 | 2.75 | 3 |
| M 8 | 1.25 | 1.2 | 2 | 2.5 | 4.7 | 5 |
| M 10 | 1.5 | 1.6 | 2.4 | 3 | 5.7 | 6 |
| M 12 | 1.75 | 2 | 2.8 | 3.6 | 7.7 | 8 |
- Source spanning title row carried verbatim: "Dimensions in mm - source DIN 438".
- Source spanning row carried verbatim: "Publication date: 09/1986 - Replaces DIN 438: 02/1972".
- Source header row narrower than the declared grid width: header prints 5 label(s) against 7 columns (data rows carry 7 cells). Header padded with empty labels; the trailing columns are the split limits of the last printed group (min/max pairs) exactly as the source lays them out — not relabelled.
- source grid ragged — 3/14 rows shorter than declared width 7; normalized with empty cells, carried verbatim (normalized with empty cells, carried verbatim; batch x152 acquisition)
| d thread size | M 1.6 | M2 | M2.5 | M3 | M3.5 | M4 | M5 | M6 | M8 | M10 | M12 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| nominal length l | |||||||||||
| 2 | |||||||||||
| 2.5 | |||||||||||
| 3 | 0.11 | ||||||||||
| 4 | 0.15 | 0.25 | |||||||||
| 5 | 0.19 | 0.33 | 0.51 | ||||||||
| 6 | 0.23 | 0.41 | 0.63 | 0.87 | |||||||
| 8 | 0.32 | 0.56 | 0.88 | 1.22 | 2.2 | ||||||
| 10 | 0.41 | 0.71 | 1.13 | 1.57 | 2.9 | 4 | |||||
| 12 | 0.86 | 1.38 | 1.92 | 3.6 | 5 | ||||||
| 14 | 1.63 | 2.27 | 4.3 | 6 | |||||||
| 16 | 1.88 | 2.62 | 5 | 7 | |||||||
| 20 | 4.32 | 6.4 | 9 | ||||||||
| 25 | 8.2 | 11.5 | |||||||||
| 30 | 14 |
- Source spanning title row carried verbatim: "DIN 438 - Approximate mass, in kg x1000 pcs, (ρ=7,85 kg/dm 3 ) - commercial items".
- source grid ragged — 1/17 rows shorter than declared width 12; normalized with empty cells, carried verbatim (normalized with empty cells, carried verbatim; batch x152 acquisition)
Materials
- Material, property class and finish specified per RFQ — the collected specification table covers geometry only
Ordering & documentation
Documents
Shipments are backed by Mill Test Certificate (MTC), Dimensional Report, Salt Spray Test Report on request, with full batch traceability from raw material to finished product. Quality management follows the owner-confirmed compliance list: ISO 9001:2015, RoHS, REACH. Exact document sets are confirmed on the order.
Quotation
- The fastener family (DIN 438 Slotted Set Screws with Cup Point) plus the standard designation from your drawing — DIN / ISO / JIS / ASTM / ANSI, or a drawing for custom parts.
- Size (diameter and length), thread type (metric or inch), property class or grade, and coating or finish.
- Quantity per size and your target delivery date.
- Destination country, and any required documents (for example a mill test certificate) so the quote includes them.
Sample & supply
Minimum order quantity is 10,000 pieces. Stock items run 3–7 days. Quantities or variants outside the standard range are confirmed at quotation.
Storage & shipping
Parts are packed for export and shipped factory-direct to buyers in Europe, Asia, the Americas and the Middle East. Store fasteners dry and protected until installation, and keep coated parts in their packaging until use; specific packing and preservation requirements can be stated on the order and confirmed at quotation.
Frequently asked questions
Why does a cup point grip better than a flat point of the same size?
The cup concentrates the clamping force onto the narrow rim of the concave point instead of spreading it over a full flat circle. The collected table shows the resulting bite circle directly: the dz cup diameter runs well below the thread diameter — at M6 it is 3 mm nominal against a 6 mm screw — so the same seating torque lands on a much smaller annulus and the rim digs in rather than slipping. The trade is surface marking: the rim leaves a defined circular imprint, which is why cup points are avoided on finished or hardened surfaces. Compare the flat-point DIN 551 on this site when the opposing face must stay unmarked, and the cone-point DIN 553 when the screw may bite its own conical seat.
What is the MOQ and lead time for these screws?
Minimum order quantity is 10,000 pieces per item. Stocked sizes ship in 3–7 days; non-stock diameters, lengths or finishes are quoted with a confirmed schedule. Common sizes in this designation are widely stocked — confirm the exact schedule against quantity and size mix at quotation.
Related knowledge
- Thread-Forming vs Thread-Cutting vs Thread-Rolling Self-Tapping Screws: What the Evidence Settles on Base Material
- Screw Family Selection by Base Material: Wood, Machine and Self-Tapping Threads, Engagement and Coating
- Hex Bolts vs Socket Head Cap Screws: What the Evidence Settles on Strength, Clearance and Cost
Request a Quote
Get factory-direct pricing from the manufacturer.
What to include in your inquiry
- ✓ Standard and property class (e.g. DIN 912, ISO 4762, class 8.8) — or a drawing for custom parts.
- ✓ Sizes, lengths and thread type (metric or inch).
- ✓ Quantity per size and your target delivery date.
- ✓ Destination country, plus any coating or finish requirement.
- ✓ Any documents you need with the shipment (e.g. mill test certificate) so the quote includes them.
- ✓ Your inquiry goes straight to the factory team by email and gets a reply within 24 hours.
- ✓ Factory-direct pricing
- ✓ Standard and custom specifications
- ✓ Factory-direct export to buyers in Europe, Asia, the Americas and the Middle East
- ✓ Full fastener family support