StandardsMAS BT (ISO 7388-2-J)IS:11173 (Part 1)
Cone tolerance AT3Original catalogue page (p. 8)(opens the scanned page in a new tab)BT shank
Drawing
Shown here: BT40 FORM A
BT shank
Dimensions
| BT No. | 30 | 35 | 40 | 45 | 50 |
|---|---|---|---|---|---|
| D | 31.75 | 38.10 | 44.45 | 57.15 | 69.75 |
| L±0.2 | 48.4 | 56.4 | 65.4 | 82.8 | 101.8 |
| d1H8 | 12.5 | 12.5 | 17 | 21 | 25 |
| G | M12 | M16 | M20 | M24 | |
| D1h8 | 46 | 53 | 63 | 85 | 100 |
| f±0.2 | 20 | 22 | 25 | 30 | 35 |
| v±0.1 | 13.6 | 14.6 | 16.6 | 21.2 | 23.2 |
| w | 8 | 10 | 12 | 15 | |
| y±0.4 | 2 | 3 | |||
| t-0.2 | 16.3 | 19.6 | 22.6 | 29.1 | 35.4 |
| bH12 | 16.1 | 19.3 | 25.7 | ||
| BTNo. | D | L | d1 | G | D1 | f | v | w | y | t | b |
|---|---|---|---|---|---|---|---|---|---|---|---|
| ±0.2 | H8 | h8 | ±0.2 | ±0.1 | ±0.4 | -0.2 | H12 | ||||
| 30 | 31.75 | 48.4 | 12.5 | M12 | 46 | 20 | 13.6 | 8 | 2 | 16.3 | 16.1 |
| 35 | 38.10 | 56.4 | 12.5 | 53 | 22 | 14.6 | 10 | 19.6 | |||
| 40 | 44.45 | 65.4 | 17 | M16 | 63 | 25 | 16.6 | 22.6 | |||
| 45 | 57.15 | 82.8 | 21 | M20 | 85 | 30 | 21.2 | 12 | 3 | 29.1 | 19.3 |
| 50 | 69.75 | 101.8 | 25 | M24 | 100 | 35 | 23.2 | 15 | 35.4 | 25.7 |
BT shank
Coolant forms
Taper accuracy
Cone tolerance AT3
Standards: ISO 1947- 1973 | IS 7615- 2003
| BT No. | 'α' Basic | Tolerance Grade AT3 | |||||
|---|---|---|---|---|---|---|---|
| Generating Angle Limits α/2 | AT α/2Secs | AT α/2μ Rads | L | ATD(D1~D2) | |||
| Min | Max | ||||||
| 30 | 16°35'39.4" | 8°17'51.2" | 8°17'57.7" | 6.5 | 31.5 | 42 | 0.0026 |
| 35 | 8°17'52.7" | 8°17'57.7" | 5 | 31.5 | 53 | 0.0033 | |
| 40 | 8°17'51.2" | 8°17'56.2" | 5 | 20.0 | 59 | 0.0024 | |
| 45 | 8°17'52.2" | 8°17'56.2" | 4 | 15.75 | 74 | 0.0030 | |
| 50 | 8°17'50.7" | 8°17'54.7" | 4 | 15.75 | 92 | 0.0029 | |
Cone tolerance AT3
Material & heat treatment
- Material
- Carburizing Alloy Steel
- Heat Treatment
- Surface Hardness HRc 58±2Case Depth 0.6-1.0 mm @ HV1 550Tensile Strength 1000 MPa Minimum