S Q 12 12 A - E 15 Q 1 2 3 4 5 6 7 8 1 S-The series of buttons with a higher precision standard 2 Q-The shape of the top part of the button Q: Spherical Z: Spherical cone T: Conical flat X: Wedge B: Eccentric wedge S: Spoon F: Pointed claw J: Auger tip 3 The diameter of the button in mm. Only 2 integers are taken.(If the diameter is only one integer, then it is preceded by zero). 4 The height of the button in mm. Only 2 integers are taken.(fit is only one digit, then it is preceded by zero). 5 Special button top and it is omitted here. 6 The angle of chamfer at the bottom of the button. E-It indicates the included angle in relation to the center line of the axis is 15° -18° F-It indicates the included angle in relation to the center line of the axis is 30° (Exception:F2 indicates 0.7>30° ) G-lt indicates the included angle in relation to the center line of the axis is 45° Xx-lt indicates the included angle in relation to the center line of the axis is other figures or other bottom shapes. 7 It indicates the height of the chamfer at the bottom and it is 10 times of the height in mm. If it is less than 2 inhtergers, then it is preceded by zero. 8 It indicates air pocket structure at the bottom. Q: Spherical hole z: Conical hole J: pointed hole It is omitted if there is no air pocket. Note: If there are no positions of 6 and 7 or they are omitted, it belongs to the series of buttons with double chamfers . Standard of tolerances of D and H| D(Diameter) | H(Height) | ||
| Nominal size | tolerance | Nominal size | tolerance |
| ≤10 | ±0.10 | ≤11 | ±0.10 |
| 11~18 | ±0.15 | ||
| ＞10 | ±0.15 | 18~25 | ±0.15 |
| ＞25 | ±0.20 | ||
