BT30 tool holders are essential components in CNC machining, designed for precision and efficiency. Part of the BT (Binding Taper) series, they use a 7/24 taper system, where “30” refers to the large end diameter of the taper (30 mm). These holders are widely used in smaller machining centers for high-speed applications.
NT /BT30 Tool Holder Tools Taper Specifications
The technical guide covers NT/BT30 tool holder tools, morse taper tools, and tool shanks with screws.
Bolt Grip Taper and National Taper
| Model | D1 | D2 | D3 | D4 | L1 | L2 | L3 | L4 | T | B1 | B2 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| BT30 | 31.75 | 13 | 46 | 38 | 48.4 | 20 | 13.6 | 24 | M12 | 16.1 | 16.3 |
| BT40 | 44.45 | 17 | 63 | 53 | 65.4 | 25 | 16.6 | 30 | M16 | 16.1 | 22.6 |
| BT45 | 57.15 | 21 | 85 | 73 | 82.8 | 30 | 21.2 | 40 | M20 | 19.3 | 29.1 |
| BT50 | 69.85 | 25 | 100 | 85 | 101.8 | 38 | 23.2 | 45 | M24 | 25.7 | 35.4 |
| Table 1 Bolt Grip Taper (Fig.1) | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Model | D1 | D2 | t1 | t2 | t3 | t5 | d1 | d3 | L | g | d5 |
| BT35 | 53 | 43 | 20 | 10 | 13 | 2 | 38.1 | 13 | 56.5 | M12x1.75 | 21.62 |
| BT40 | 63 | 53 | 25 | 10 | 16.6 | 2 | 44.45 | 17 | 65.4 | M16x2 | 25.3 |
| BT45 | 85 | 73 | 30 | 12 | 21.2 | 3 | 57.15 | 21 | 82.8 | M20x25 | 33.1 |
| BT50 | 100 | 85 | 35 | 15 | 23.2 | 3 | 69.85 | 25 | 101.8 | M24x3 | 40.1 |
| BT60 | 155 | 135 | 45 | 20 | 28.2 | 3 | 107.95 | 31 | 161.8 | M30x3.5 | 60.7 |
| Table 2 National Taper (Fig 2) | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| NT | D1 | d1 | I | I1 | g | I2 | I3 | d3 | I4 | D2 | I5 | |
| Metric Screw | Wit Screw | |||||||||||
| 30 | 31.75 | 17.4 | 70 | 50 | M12 | W 1/2 | 24 | 50 | 16.5 | 6 | 50 | 8 |
| 40 | 44.45 | 25.3 | 95 | 67 | M16 | W 5/8 | 30 | 70 | 24 | 7 | 63 | 10 |
| 50 | 69.85 | 39.6 | 130 | 105 | M24 | W 1/2 | 45 | 90 | 38 | 11 | 100 | 13 |
| 60 | 107.95 | 60.2 | 210 | 165 | M30 | W 11/4 | 56 | 110 | 58 | 12 | 170 | 15 |
Morse Taper
| Table 3 shank with tongue (Fig 3) | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Morse Taper Number | D | a | D1 | d1 | d2 | I1 | I2 | d | c | e | R | r |
| 0 | 9.045 | 3 | 9.201 | 6.104 | 6 | 56.5 | 59.5 | 3.9 | 6.5 | 10.5 | 4 | 1 |
| 1 | 12.065 | 3.5 | 12.24 | 8.972 | 8.7 | 62 | 65.5 | 5.2 | 8.5 | 13.5 | 5 | 1.2 |
| 2 | 17.78 | 5 | 18.03 | 14.034 | 13.5 | 75 | 80 | 6.3 | 10 | 16 | 6 | 1.6 |
| 3 | 23.825 | 5 | 24.076 | 19.107 | 18.5 | 94 | 99 | 7.9 | 13 | 20 | 7 | 2 |
| 4 | 31.267 | 6.5 | 31.605 | 25.164 | 24.5 | 117.5 | 124 | 11.9 | 16 | 24 | 8 | 2.5 |
| 5 | 44.399 | 6.5 | 44.741 | 36.531 | 35.7 | 149.5 | 156 | 15.9 | 19 | 29 | 10 | 3 |
| 6 | 63.348 | 8 | 63.765 | 52.399 | 51 | 210 | 218 | 19 | 27 | 40 | 13 | 4 |
| 7 | 83.058 | 10 | 83.578 | 68.185 | 66.8 | 286 | 296 | 28.6 | 35 | 54 | 19 | 5 |
| Table 4 shank with screw (Fig 4) | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Morse Taper Number | D | a | D1 | d | d1 | I1 | I2 | t | r | d2 | K |
| 0 | 9.045 | 3 | 9.201 | 6.442 | 6 | 50 | 53 | 4 | 0.2 | ─ | ─ |
| 1 | 12.065 | 3.5 | 12.24 | 9.396 | 9 | 53.5 | 57 | 5 | 0.2 | M6 | 16 |
| 2 | 17.78 | 5 | 18.03 | 14.583 | 14 | 64 | 69 | 5 | 0.2 | M10 | 24 |
| 3 | 23.825 | 5 | 24.076 | 19.759 | 19 | 81 | 86 | 7 | 0.6 | M12 | 28 |
| 4 | 31.267 | 6.5 | 31.605 | 25.943 | 25 | 102.5 | 109 | 9 | 1 | M16 | 32 |
| 5 | 44.399 | 6.5 | 44.741 | 37.584 | 35.7 | 129.5 | 136 | 9 | 2.5 | M20 | 40 |
| 6 | 63.348 | 8 | 63.765 | 53.859 | 51 | 182 | 190 | 12 | 4 | M24 | 50 |
| 7 | 83.058 | 10 | 83.578 | 70.052 | 65 | 250 | 260 | 18.5 | 5 | M33 | 80 |
Originate Data Source: Q042
This table helps select suitable tool holders by summarizing their specifications for machining. This, in turn, improves work efficiency and enhances the quality of the parts.