BT Mini ER Collet Chucks – BT30, BT40 and BT50 (MAS 403)

A mini ER collet chuck is a slim-nose ER-M collet chuck for small tools and deep cavities. PTP makes them with a BT shank (MAS 403 / JIS B6339, ISO 7388-2 type J) in BT30, BT40 and BT50: ER11M to ER25M collets, gauge lengths 60–150 mm, 23 ordering codes in all. They are pulled into the spindle by MAS-BT or JIS B6339 pull studs: M12 on BT30, M16 on BT40 and M24 on BT50. Taper AT3 or better, TIR 0.005 mm max, balanced G2.5 @ 25,000 rpm.

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Mini ER Collet Chucks, BT shank: technical drawing with dimensions — Mini ER Collet Chucks with a BT shank, from the PTP catalogue. Click to open it full size.

All 23 BT mini ER collet chucks

One table per taper size. Every ordering code opens its own page with its dimensions (mm).

BT30 mini ER collet chucks: 8 ordering codes

Ordering code	Collet	Clamping Range	Nut Ø (d)	Gauge Length (GPL)
47BT30ER11M60	ER11M	0.5–7 mm	16 mm	60 mm
47BT30ER11M100	ER11M	0.5–7 mm	16 mm	100 mm
47BT30ER16M60	ER16M	1–10 mm	22 mm	60 mm
47BT30ER16M100	ER16M	1–10 mm	22 mm	100 mm
47BT30ER20M60	ER20M	1–13 mm	28 mm	60 mm
47BT30ER20M100	ER20M	1–13 mm	28 mm	100 mm
47BT30ER25M60	ER25M	1–16 mm	35 mm	60 mm
47BT30ER25M100	ER25M	1–16 mm	35 mm	100 mm

BT40 mini ER collet chucks: 9 ordering codes

Ordering code	Collet	Clamping Range	Nut Ø (d)	Gauge Length (GPL)
47BT40ER11M70	ER11M	0.5–7 mm	16 mm	70 mm
47BT40ER11M100	ER11M	0.5–7 mm	16 mm	100 mm
47BT40ER16M70	ER16M	1–10 mm	22 mm	70 mm
47BT40ER16M100	ER16M	1–10 mm	22 mm	100 mm
47BT40ER20M70	ER20M	1–13 mm	28 mm	70 mm
47BT40ER20M100	ER20M	1–13 mm	28 mm	100 mm
47BT40ER25M70	ER25M	1–16 mm	35 mm	70 mm
47BT40ER25M100	ER25M	1–16 mm	35 mm	100 mm
47BT40ER25M150	ER25M	1–16 mm	35 mm	150 mm

BT50 mini ER collet chucks: 6 ordering codes

Ordering code	Collet	Clamping Range	Nut Ø (d)	Gauge Length (GPL)
47BT50ER16M80	ER16M	1–10 mm	22 mm	80 mm
47BT50ER16M100	ER16M	1–10 mm	22 mm	100 mm
47BT50ER20M80	ER20M	1–13 mm	28 mm	80 mm
47BT50ER20M100	ER20M	1–13 mm	28 mm	100 mm
47BT50ER25M80	ER25M	1–16 mm	35 mm	80 mm
47BT50ER25M100	ER25M	1–16 mm	35 mm	100 mm

Questions about BT mini ER collet chucks

Which pull stud does a BT mini ER collet chuck take?

The pull stud of its taper size: M12 on BT30, M16 on BT40 and M24 on BT50. Use a MAS-BT pull stud with the head angle your drawbar takes (45°, 60° or 90°), or a JIS B6339 stud with a 15° head (BT40 and BT50).

BT30 pull studs BT40 pull studs BT50 pull studs

What goes with a BT mini ER collet chuck?

DIN 6499 ER collets (ER11, ER16, ER20 and ER25) and the ER-M mini collet nut of that size (36CCNER11M, 36CCNER16M, 36CCNER20M and 36CCNER25M).

ER collets DIN 6499 Mini ER collet nuts