Compared with carbide stick blanks or short standard blanks, preformed blanks are more difficult on technique to ensure outer diameter, half diameter, roundness, roughness and straightness. We can manufacture it by custom requirement on drawing, even grind it with tolerance +0.000 ~ -0.005mm on outer diameter. So customer can soldered it directly on hollow shank for application.
Preformed blanks with single coolant hole, two coolant hole and kidney coolant hole are all available in stock.
Grade for Carbide blanks tips GUHRING | K10-K15 | DK105 | 1.0um | 6% Cobalt | 92.3HRA |
CERATIZIT | K10-K15 | CTF12E(H20X/HC20) | 0.8um | 6% Cobalt | 92.2HRA |
Harmetall-ESTECH | K10-K20 | RF13 | 0.8um | 6.5% Cobalt | 92.4HRA |
STAR CUTTER | K30-K40 | HB110 | 0.8um | 10% Cobalt | 92.0HRA |
KONETOOL | K30-K40 | KT30U | 0.8um | 10% Cobalt | 92.1HRA |
KONETOOL | K10-K15 | KT10U | 0.6um | 6% Cobalt | 93.2HRA |

Carbide Tip - Cutting Edge Geometry

Changes to the cutting edge geometry of the single-lip drill can affect the drilled surface, the chip shape, bore tolerance, drill centring, chip removal, surface quality and tool life.
With our standard grind facets virtually and drilling tasks can be executed successfully. When drilling deep holes in particularly long chipping materials and in materials that are difficult to machine it is generally necessary to use special grind facets, in some cases with chip-separators or chip-breakers.
Carbide Tip - Head Forms

Blanks Dia. [mm] | L [mm] | Gundrill Dia. [mm] |
6.5 | 28 / 32 | 6.0 |
7.0 | 28 / 32 | 6.5 |
7.5 | 30 / 34 | 7.0 |
8.0 | 30 / 34 | 7.5 |
8.5 | 32 / 36 | 8.0 |
9.0 | 32 / 36 | 8.5 |
9.5 | 32 / 36 | 9.0 |
10.0 | 32 / 36 | 9.5 |
10.5 | 32 / 36 | 10.0 |
11.0 | 32 / 38 | 10.5 |
11.5 | 32 / 38 | 11.0 |
12.0 | 35 / 40 | 11.5 |
12.5 | 35 / 40 | 12.0 |
13.0 | 35 / 40 | 12.5 |
13.5 | 35 / 40 | 13.0 |
14.0 | 35 / 40 | 13.5 |
14.5 | 35 / 40 | 14.0 |
15.0 | 38 / 42 | 14.5 |
15.5 | 38 / 42 | 15.0 |
16.0 | 40 / 45 | 15.5 |
16.5 | 40 / 45 | 16.0 |
17.0 | 40 / 45 | 16.5 |
17.5 | 40 / 45 | 17.0 |
18.0 | 45 / 51 | 17.5 |
18.6 | 40 / 45 | 18.0 |
19.1 | 45 / 51 | 18.5 |
19.6 | 45 / 51 | 19.0 |
20.1 | 50 / 55 | 19.5 |
20.6 | 45 / 50 | 20.0 |
21.1 | 50 / 55 | 20.5 |
21.7 | 50 / 55 | 21.0 |
22.1 | 50 / 58 | 21.5 |
22.7 | 45 / 50 / 58 | 22.0 |
23.1 | 50 / 58 / 61 | 22.5 |
23.7 | 50 / 58 | 23.0 |
24.1 | 50 / 58 | 23.5 |
24.7 | 50 / 58 | 24.0 |
25.1 | 55 / 61 | 24.5 |
25.8 | 50 / 55 / 61 | 25.0 |
26.8 | 55 / 61 | 26.0 |
27.8 | 55 / 61 | 27.0 |
28.8 | 55 / 63 | 28.0 |
29.8 | 55 / 63 | 29.0 |
30.9 | 55 / 60 / 65 | 30.0 |
31.9 | 60 / 65 | 31.0 |
32.9 | 60 / 65 | 32.0 |
33.9 | 60 / 65 | 33.0 |
34.9 | 60 / 65 | 34.0 |
35.9 | 60 / 65 | 35.0 |
36.9 | 60 / 65 | 36.0 |
37.9 | 60 / 65 | 37.0 |
38.9 | 60 / 65 | 38.0 |
39.9 | 60 / 65 | 39.0 |
40.9 | 60 / 65 | 40.0 |
42.9 | 65 | 42.0 |
43.9 | 65 | 43.0 |
45.9 | 70 | 45.0 |