SK50 ER collet chucks
SK50 (ISO 50) ER40 Collet Chucks (DIN 69871): Gauge Lengths 80 and 100 mm
SK50 (ISO 50) ER40 collet chucks hold round-shank drills, reamers and end mills in a DIN 6499 ER40 collet, closed by the ER40 clamping nut (M30x1.5). PTP makes them with an SK shank (DIN 69871 / ISO 7388-1) in gauge lengths of 80 and 100 mm, for tool shanks of 3–26 mm. Ordering codes: 2. SK50 holders are pulled into the spindle by an M24 DIN 69872 pull stud. Taper AT3 or better, TIR 0.005 mm max, balanced G2.5 @ 25,000 rpm.
SK50 (ISO 50) ER40 collet chucks: 2 ordering codes
Every ordering code opens its own page with the drawing and every dimension (mm).
| Ordering code | Clamping Range | Nut Ø (d) | Gauge Length (GPL) |
|---|---|---|---|
| 47ISO50ER4080 | 3–26 mm | 63 mm | 80 mm |
| 47ISO50ER40100 | 3–26 mm | 63 mm | 100 mm |
SK50 ER40 collet chuck
PTP catalogue drawing, dimensions in mm

Questions about SK50 ER40 collet chucks
What is the clamping range of an SK50 ER40 collet chuck?
3–26 mm. ER40 collets to DIN 6499 clamp tool shanks from 3 to 26 mm, one collet for each size step.
Which pull stud does an SK50 ER40 collet chuck need?
An M24 SK50 pull stud: DIN 69872 with a 15° head.
Which nut and collets fit an SK50 ER40 collet chuck?
ER40 collets to DIN 6499 and the ER40 clamping nut: slotted 36CCNER40. For coolant-through tools, an ER40 sealing ring (15 sizes, 36CCNER40SR060 to 36CCNER40SR200).
