BT Threaded Mill Adapters – BT30, BT40 and BT50 (MAS 403)

A threaded mill adapter drives milling cutters with a threaded (screw-in) shank. PTP makes them with a BT shank (MAS 403 / JIS B6339, ISO 7388-2 type J) in BT30, BT40 and BT50: M6 to M16 threads, gauge lengths 60–295 mm, 33 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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Threaded Mill Adapters, BT shank: technical drawing with dimensions — Threaded Mill Adapters with a BT shank, from the PTP catalogue. Click to open it full size.

All 33 BT threaded mill adapters

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

BT30 threaded mill adapters: 6 ordering codes

Ordering code	Thread	Bore Ø (d)	Gauge Length (GPL)	D1	C
46BT30TMA0660	M6	6.5 mm	60 mm	11 mm	14.5 mm
46BT30TMA0685	M6	6.5 mm	85 mm	11 mm	16 mm
46BT30TMA0860	M8	8.5 mm	60 mm	13.5 mm	18.5 mm
46BT30TMA0885	M8	8.5 mm	85 mm	13.5 mm	20 mm
46BT30TMA1060	M10	10.5 mm	60 mm	18.5 mm	23 mm
46BT30TMA1085	M10	10.5 mm	85 mm	18.5 mm	24.5 mm

BT40 threaded mill adapters: 19 ordering codes

Ordering code	Thread	Bore Ø (d)	Gauge Length (GPL)	D1	C
46BT40TMA0660	M6	6.5 mm	60 mm	11 mm	14.5 mm
46BT40TMA0685	M6	6.5 mm	85 mm	11 mm	16 mm
46BT40TMA0860	M8	8.5 mm	60 mm	13.5 mm	18.5 mm
46BT40TMA0885	M8	8.5 mm	85 mm	13.5 mm	20 mm
46BT40TMA08110	M8	8.5 mm	110 mm	13.5 mm	21.5 mm
46BT40TMA1060	M10	10.5 mm	60 mm	18.5 mm	23 mm
46BT40TMA1085	M10	10.5 mm	85 mm	18.5 mm	24.5 mm
46BT40TMA10135	M10	10.5 mm	135 mm	18.5 mm	27.5 mm
46BT40TMA10185	M10	10.5 mm	185 mm	18.5 mm	37 mm
46BT40TMA1260	M12	12.5 mm	60 mm	23 mm	28.5 mm
46BT40TMA1285	M12	12.5 mm	85 mm	23 mm	30 mm
46BT40TMA12110	M12	12.5 mm	110 mm	23 mm	31.5 mm
46BT40TMA12135	M12	12.5 mm	135 mm	23 mm	33 mm
46BT40TMA12185	M12	12.5 mm	185 mm	23 mm	42.5 mm
46BT40TMA1660	M16	17 mm	60 mm	30 mm	35.5 mm
46BT40TMA1685	M16	17 mm	85 mm	30 mm	37 mm
46BT40TMA16110	M16	17 mm	110 mm	30 mm	38.5 mm
46BT40TMA16135	M16	17 mm	135 mm	30 mm	40.5 mm
46BT40TMA16185	M16	17 mm	185 mm	30 mm	50 mm

BT50 threaded mill adapters: 8 ordering codes

Ordering code	Thread	Bore Ø (d)	Gauge Length (GPL)	D1	C
46BT50TMA1295	M12	12.5 mm	95 mm	23 mm	35 mm
46BT50TMA12145	M12	12.5 mm	145 mm	23 mm	41 mm
46BT50TMA12195	M12	12.5 mm	195 mm	23 mm	42.5 mm
46BT50TMA1695	M16	17 mm	95 mm	30 mm	42.5 mm
46BT50TMA16145	M16	17 mm	145 mm	30 mm	49 mm
46BT50TMA16195	M16	17 mm	195 mm	30 mm	50 mm
46BT50TMA16245	M16	17 mm	245 mm	30 mm	55 mm
46BT50TMA16295	M16	17 mm	295 mm	30 mm	59.5 mm

Questions about BT threaded mill adapters

Which pull stud does a BT threaded mill adapter 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 threaded mill adapter?

Milling cutters with a threaded (screw-in) shank: M6, M8, M10, M12 and M16.