UC型钻头，减少钻头与孔壁摩擦，能保证良好的孔壁粗糙度。
D为刃径，L为刃长
| 型号 | D[mm] | L[mm] |
| J-UC | 0.20 | 4.0 |
| 0.25 | 4.5 | |
| 0.30 | 5.5 | |
| 0.35 | 6.5 | |
| 0.40 | 7.0 | |
| 0.45 | 7.0 | |
| 0.50 | 5.5/7.0 | |
| 0.55 | 5.5/7.0 | |
| 0.60 | 7.0/8.5 | |
| 0.65 | 7.0/8.5 | |
| 0.70 | 8.5 | |
| 0.75 | 8.5 | |
| 0.80 | 9.5 | |
| 0.85 | 9.5 | |
| 0.90 | 9.5 | |
| 0.95 | 9.5 | |
| 1.00 | 10.5 |
