BT50 ER collet chucks
BT50 ER50 Collet Chucks (MAS 403): Gauge Lengths 100 and 160 mm
BT50 ER50 collet chucks hold round-shank drills, reamers and end mills in a DIN 6499 ER50 collet, closed by the ER50 clamping nut (M30x1.5). PTP makes them with a BT shank (MAS 403 / JIS B6339, ISO 7388-2 type J) in gauge lengths of 100 and 160 mm, for tool shanks of 10–34 mm. Ordering codes: 2. BT50 holders are pulled into the spindle by an M24 MAS-BT or JIS B6339 pull stud. Taper AT3 or better, TIR 0.005 mm max, balanced G2.5 @ 25,000 rpm.
BT50 ER50 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) |
|---|---|---|---|
| 47BT50ER50100 | 10–34 mm | 78 mm | 100 mm |
| 47BT50ER50160 | 10–34 mm | 78 mm | 160 mm |
BT50 ER50 collet chuck
PTP catalogue drawing, dimensions in mm

Questions about BT50 ER50 collet chucks
What is the clamping range of a BT50 ER50 collet chuck?
10–34 mm. ER50 collets to DIN 6499 clamp tool shanks from 10 to 34 mm, one collet for each size step.
Which pull stud does a BT50 ER50 collet chuck need?
An M24 BT50 pull stud: MAS-BT with the head angle your drawbar takes (45°, 60° or 90°), or JIS B6339 with a 15° head.
Which nut and collets fit a BT50 ER50 collet chuck?
ER50 collets to DIN 6499 and the ER50 clamping nut: slotted 36CCNER50.
