BT JIS Norm Dimensions

JIS B 6339 with coolant through A/AD/B from DIN (ISO 7388-2-J/JD/JF)

The B through coolant design of ADB holders is made according to DIN 69871-B.

Machine side			d1	d2	d4	d5	d7	d9	e1	u	l1	l6	l9	b	y
BT30	A/AD	mm	31.75	12.5	38	46	M12	–	–	22	48.4	16.3	11	16.1	2
BT30	A/AD	inch	1.250	0.492	1.496	1.811	M12	–	–	0.866	1.906	0.642	0.433	0.634	0.079
BT40	A/AD	mm	44.45	17	53	63	M16	–	–	27	65.4	22.5	14.5	16.1	2
BT40	A/AD	inch	1.750	0.669	2.087	2.480	M16	–	–	1.063	2.575	0.886	0.571	0.634	0.079
BT40 ADB	A/AD/B	mm	44.45	17	53	63	M16	4	27	27	65.4	22.5	14.5	16.1	2
BT40 ADB	A/AD/B	inch	1.750	0.669	2.087	2.480	M16	0.157	1.063	1.063	2.575	0.886	0.571	0.634	0.079
BT50	A/AD	mm	69.85	25	85	100	M24	–	–	38	101.8	35.4	20.5	25.7	3
BT50	A/AD	inch	2.750	0.984	3.346	3.937	M24	–	–	1.496	4.008	1.394	0.807	1.012	0.118
BT50 ADB	A/AD/B	mm	69.85	25	85	100	M24	6	42	38	101.8	35.4	20.5	25.7	3
BT50 ADB	A/AD/B	inch	2.750	0.984	3.346	3.937	M24	0.236	1.654	1.496	4.008	1.394	0.807	1.012	0.118

BT holders with a front end diameter in excess of diameter d5, are produced with a flange clearance length: BT30 = ∅ 45 mm x 3 mm; BT40 = ∅ 62 mm x 8 mm; BT50 = ∅ 98 mm x 12 mm. This is compatible with the BT JIS norm which permits free dimensions on workpiece side.