← AskMachinist · Guides · Calculator · 🔎 Search
Slotted Cone Point Set Screw Dimensions (ISO 7434 / DIN 553, M1.6 to M12)
Guide · Updated October 28, 2026
ISO 7434 covers slotted set screws with cone point (DIN 553), from M1.6 to M12. Values agree across the ISO 7434 draft preview (iTeh), globalfastener, fasteners.eu, DigiPich and fasten.it, and the one conflicting cell is dashed. Check your supplier for critical work.
Need an exact reference size?
Build any gage block stack with the free Gage Block Calculator. Free, no login.
Step by step
- Read the thread: Measure the major diameter and pitch. The chart covers coarse M1.6 to M12.
- Pick the screwdriver: Choose a blade that fills the slot width n, at least n nom thick.
- Spot the shaft: The cone locates in a spot or dimple. dt max is the tip diameter, and sizes up to M5 have a near-sharp point.
- Mind the torque: A slot carries much less torque than a hex socket. Use ISO 4027 cone point socket screws for higher loads.
- Lock it: Add threadlocker for vibration.
ISO 7434 slotted cone point set screw dimensions (mm)
Columns: thread, pitch P, cone tip diameter dt max, slot width n nom, min and max, slot depth t min and max.
- Size | P | dt max | n nom | n min | n max | t min | t max
- M1.6 | 0.35 | 0.16 | 0.25 | 0.31 | 0.45 | 0.56 | 0.74
- M2 | 0.4 | 0.2 | 0.25 | 0.31 | 0.45 | 0.64 | 0.84
- M2.5 | 0.45 | 0.25 | 0.4 | 0.46 | 0.6 | 0.72 | 0.95
- M3 | 0.5 | 0.3 | 0.4 | 0.46 | 0.6 | 0.8 | 1.05
- (M3.5) | 0.6 | 0.35 | 0.5 | 0.56 | 0.7 | 0.96 | 1.21
- M4 | 0.7 | 0.4 | 0.6 | 0.66 | 0.8 | 1.12 | 1.42
- M5 | 0.8 | 0.5 | 0.8 | 0.86 | 1 | — | 1.63
- M6 | 1 | 1.5 | 1 | 1.06 | 1.2 | 1.6 | 2
- M8 | 1.25 | 2 | 1.2 | 1.26 | 1.51 | 2 | 2.5
- M10 | 1.5 | 2.5 | 1.6 | 1.66 | 1.91 | 2.4 | 3
- M12 | 1.75 | 3 | 2 | 2.06 | 2.31 | 2.8 | 3.6
Worked example: M6 slotted cone point
An M6 slotted cone point has a slot 1.06 to 1.2 mm wide and 1.6 to 2.0 mm deep, and a tip of at most 1.5 mm. Spot the shaft with a 90° drill point.
Common problems
- Slot cams out: use a blade that fills the slot, or switch to an ISO 4027 socket screw.
- Part creeps: the cone is not in its spot, so re-spot it in line.
- Screw loosens: add threadlocker.
FAQ
What is ISO 7434?
The slotted set screw with cone point. DIN 553 is the German equivalent. The cone digs in or seats in a spot for positive location.
Slotted or socket cone point?
Slotted (ISO 7434) is for light duty and adjusters. The hex socket cone point (ISO 4027) takes far more torque.
Why is M5 t min dashed?
ISO 7434, globalfastener and fasten.it give 1.28, while fasteners.eu and DigiPich give 1.25, so the cell is dashed.
Why does M12 n use 2.06 / 2.31?
The ISO draft, globalfastener, fasteners.eu and DigiPich agree on 2.06 / 2.31. Only fasten.it prints 2.1 / 2.3.
What was skipped?
The DIN-only sizes M1 to M1.4, dt min (not specified) and M5 t min.
Related guides and calculators
- Slotted cup point set screws (ISO 7436)
- Slotted dog point set screws (ISO 7435)
- Slotted flat point set screws (ISO 4766 / DIN 551)
- Cone point set screws (ISO 4027 / DIN 914)
- Flat point set screws (ISO 4026)
- Cup point set screws (ISO 4029 / DIN 916)
- All free machinist calculators
Build your stack in seconds
The free Gage Block Calculator finds the fewest-block combination for inch and metric sets, with wear blocks. No login.
Questions? Ask a machinist.
General shop information only — follow your drawing, tool maker's data and your quality system.