A centre drill is a form drill that drills a locating hole in the centre of a workpiece for turning or grinding. It is widely used in machining, machinery, shipbuilding and other industries. Centre drills are usually made of high speed steel (HSS). The geometry of these drills is characterised by the short length of the front end and the stepped shape of the tool. The diameter of the front part is the nominal diameter of the tool, ensuring high centring accuracy in the hole.
Solid carbide center drill
Engineering Data
four-sided grinding
spiral fluted
| d1 | d2 | dl | d2 | |||||
| DIN | L3 | L1 | (h6) | DIN | L3 | L1 | (h6) | |
| mm | mm | mm | mm | mm | mm | mm | mm | |
| 0.5 | 2.12 | 25 | 3.15 | 2.5 | 6.7 | 45 | 6.3 | |
| 0.8 | 2.65 | 25 | 3.15 | 3.15 | 8.5 | 50 | 8 | |
| 1 | 3 | 31.5 | 3.15 | 4 | 10.6 | 56 | 10 | |
| 1.25 | 3.35 | 31.5 | 3.15 | 5 | 13.2 | 63 | 12.5 | |
| 1.6 | 4.25 | 31.5 | 4 | 6.3 | 17 | 71 | 16 | |
| 2 | 5.3 | 40 | 5 |
Engineering Data
four-sided grinding
spiral fluted
| dl | d2 | dl | d2 | |||||
| DIN | L2 | Ll | (h6) | DIN | L3 | L1 | (h6) | |
| mm | mm | mm | mm | mm | mm | mm | mm | |
| 0.5 | 3 | 25 | 3,15 | 2.5 | 3 | 45 | 6.3 | |
| 0.8 | 1.1 | 25 | 3.15 | 3.15 | 3.9 | 50 | 8 | |
| 1 | 13 | 31.3 | 3.15 | 4 | 5 | 56 | 10 | |
| 1.25 | 1.6 | 31.3 | 3.15 | |||||
| 1.6 | 2 | 35.3 | 4 | 5 | 6.3 | 63 | 12.5 | |
| 2 | 2.5 | 40 | 5 | 6.3 | 8 | 71 | 16 |
Engineering Data
pilot drill
short flute length
point ground：relieved cone
| dl | d2 | dl | d2 | |||||
| (h6) | L2 | L1 | (h6) | (h6) | L2 | L1 | (h6) | |
| mm | mm | mm | mm | mm | mm | mm | mm | |
| 5 | 10 | 62 | 5 | 12 | 25 | 102 | 12 | |
| 6 | 15 | 66 | 6 | 16 | 35 | 115 | 16 | |
| 8 | 20 | 79 | 8 | 20 | 40 | 131 | 20 | |
| 10 | 22 | 89 | 10 |
Engineering Data
pilot drill
short flute length
point ground: relieved cone
| d1 | d2 | d1 | d2 | |||||
| (h6) | L2 | L1 | (h6) | (h6) | L2 | L1 | (h6) | |
| mm | mm | mm | mm | mm | mm | mm | mm | |
| 5 | 10 | 62 | 5 | 12 | 25 | 102 | 12 | |
| 6 | 15 | 66 | 6 | 16 | 35 | 115 | 16 | |
| 8 | 20 | 79 | 8 | 20 | 40 | 131 | 20 | |
| 10 | 22 | 89 | 10 |
Engineering Data
three cutting edges
for counterbores acc
DIN 74
| d1 | d2 | d1 | d2 | |||||
| (z9) | d3 | L1 | (h7) | (z9) | d3 | L1 | (h7) | |
| mm | mm | mm | mm | mm | mm | mm | mm | |
| 6.3 | 1.5 | 45 | 5 | 15 | 3.2 | 60 | 10 | |
| 8.3 | 2 | 50 | 6 | 16.5 | 3.2 | 60 | 10 | |
| 10.4 | 2.5 | 50 | 6 | 20.5 | 3.5 | 63 | 10 | |
| 12.4 | 2.8 | 56 | 8 | 25 | 3.8 | 67 | 10 | |
| 31 | 4.2 | 76 | 12 |
Engineering Data
special four-sided grinding
R plastic
straight slot
| d | R | d1 | L | d | R | d1 | L | |
| 3 | 0.5 | 4 | 38 | 4 | 3 | 10 | 60 | |
| 2 | 1 | 4 | 38 | 2 | 4 | 10 | 60 | |
| 5 | 0.5 | 6 | 38 | 6 | 3 | 12 | 60 | |
| 4 | 1 | 6 | 38 | 4 | 4 | 12 | 60 | |
| 2 | 2 | 6 | 38 | 10 | 3 | 16 | 70 | |
| 7 | 0.5 | 8 | 40 | 8 | 4 | 16 | 70 | |
| 6 | 1 | 8 | 40 | 6 | 5 | 70 | ||
| 4 | 2 | 8 | 40 | 14 | 3 | 20 | 80 | |
| 7 | 1.5 | 10 | 60 | 12 | 4 | 20 | 80 | |
| 6 | 2 | 10 | 60 | 10 | 5 | 20 | 80 | |
| 8 | 6 | 20 | 80 |
