DIN 438 Slotted set screws with cup point
DIN 438 is the slotted headless set screw with a cup point: the end is hollowed out to leave a sharp circular rim. When tightened, that rim bites a thin annular ring into the shaft, so the screw locks against rotation without needing a drilled dimple. This makes the cup point the general-purpose locking choice among slotted set screws — it holds firmly on plain round bar and resists vibration well. Definite Metal manufactures DIN 438 in CW614N brass from M3 to M10, with custom lengths on request. Part of our brass grub screws range.
What the Cup Point Does
The annular rim concentrates clamping force into a narrow circle of contact, giving a high locking grip for the tightening torque applied. Unlike a flat point it does mark the shaft, and unlike a cone point it needs no pre-drilled seat — you simply tighten it onto the round surface. That balance of strong hold and no shaft preparation is why cup point is the most widely stocked set-screw point. For repeated adjustment without marking, switch to a flat point (DIN 551); for positive location in a hole, a long dog point (DIN 417).
Why Brass
Brass DIN 438 is used where a reliable lock is combined with corrosion resistance, non-magnetic behaviour or electrical contact — shaft collars in instruments, meter and transformer assemblies, terminal clamping, and marine or decorative fittings. CW614N forms a clean, concentric cup rim in high-speed turning. Because brass is softer than hardened steel, for locking onto a hard steel shaft under high vibration a steel or stainless cup point gives a deeper bite, and we can supply either.
DIN 438 Dimensions (mm)
| Thread d | Pitch P | Cup rim dia. dz (max) | Slot width n | Slot depth t (min) | Length l range |
|---|---|---|---|---|---|
| M3 | 0.5 | 1.4 | 0.4 | 0.8 | 3–25 |
| M4 | 0.7 | 2.0 | 0.6 | 1.12 | 4–25 |
| M5 | 0.8 | 2.5 | 0.8 | 1.28 | 5–30 |
| M6 | 1.0 | 3.0 | 1.0 | 1.6 | 5–35 |
| M8 | 1.25 | 5.0 | 1.2 | 2.0 | 8–40 |
| M10 | 1.5 | 6.0 | 1.6 | 2.4 | 10–40 |
Standard nominal values; other sizes to order.
DIN 438 corresponds to ISO 7436 — see also our ISO 7436 page, which additionally covers small sizes M1.6–M2.5. Also cross-referenced as CSN 021182 and PN 82274.
Materials — Brass Grades
| Grade | Standard | Character | Typical composition |
|---|---|---|---|
| CW614N | EN 12164 | Free-machining brass (standard) | ~58% Cu, ~3% Pb, bal. Zn |
| CW617N | EN 12165 | Hot-forging brass | ~58% Cu, ~2% Pb, bal. Zn |
| IS 319 | IS 319 | Free-cutting brass (Indian) | ~57–59% Cu, Pb, bal. Zn |
| MS / SS 303/304/316 | — | On request | Mild steel or stainless |
Also available in MS and SS 303/304/316 on request.
Finish Options
Natural brass as standard; on request nickel plating, tin plating, or bright dip / passivation. Steel and stainless variants can be supplied plain, zinc plated, or black oxide.
Manufacturing & Export Capability
Custom manufacturing from drawing/sample · MOQ: 500 pcs (typical) · Lead time 1–2 weeks · ISO 9001:2015 · Export packing · FOB Mundra / CIF worldwide · Brass specialist in Jamnagar, India’s brass city
18+ years of manufacturing experience · 19 skilled workers · Sales@definitemetal.com
Applications & Industries
DIN 438 brass cup-point set screws lock shaft collars, knobs, gears and pulleys on plain round bar, clamp conductors in electrical terminals, and secure settings in instruments, meters and marine hardware where corrosion resistance and a firm, vibration-resistant hold are both needed.
Frequently Asked Questions
It locks firmly on plain round bar without any shaft preparation — no dimple to drill and no hole to align — so it is the easiest strong-holding point to use in general assembly.
It leaves a small ring-shaped bite where the rim grips. That mark is what gives the hold; if you cannot mark the shaft, choose a flat point instead.
Cup point holds on a plain shaft with no dimple; cone point needs a drilled seat but locates more precisely. Choose by whether the shaft can be pre-drilled.
ISO 7436. Note ISO 7436 also covers smaller sizes M1.6 to M2.5 not listed in the DIN 438 range.
M3 to M10 with custom lengths; typical MOQ is 500 pcs per size, lead time 1 to 2 weeks.