Precise and efficient drilling
from 0.1 mm (.004”)

CrazyDrill Flex 20 x d, 30 x d, 50 x d

Mikron Tool recommends pilot drilling for all types of CrazyDrill Flex:

Piloting and deep drilling

CrazyDrill Flex represents a well-coordinated program with the Flexpilot and CrazyDrill Pilot SST-Inox (pilot resp. short drill) and CrazyDrill Flex (flexible long drill). The base for precise deep hole drilling and stable machining is provided by the pilot drilling (CrazyDrill Flexpilot, CrazyDrill Pilot SST-Inox or, on inclined surfaces, CrazyDrill Crosspilot). The pilot drill ensures a high position accuracy due to its short and sturdy construction. The pilot hole is the guidance for the subsequent CrazyDrill Flex 20 x d, 30 x d or 50 x d to guide it cylindrically and guarantee the straightness and perpendicularity of the deep hole.

The quality of the drilling as well as the stable machining process (no jamming) are guaranteed by means of a predetermined tool tolerance.

Tolerance of the CrazyDrill Flexpilot: - 0.0 mm /+ 0.003 mm (- .0” /+ .00012”) (k4)

Tolerance of the CrazyDrill Pilot SST-Inox: + 0.002 mm / + 0.006 mm (+ .00008” / + .00024”) (m5)

Tolerance of the CrazyDrill Crosspilot (inclined drilling): - 0.0 mm /+ 0.006 mm (- .0” /+ .00024”) (k6)

Tolerance of the follow-up drill CrazyDrill Flex up to 50 x d: - 0.003 mm /- 0.006 mm (- .00012” /- .00024”)

Drilling process

General information

In the industry of metal work tools, shorter processing times are always in high demand. At the same time, the requirements to the manufacturing precision and the process reliability are extremely high. In order to fulfill these requirements, the "machine tool – spindle – tool – tool holder" system need to be considered as a whole (see additional info).

For the use of the types of drill bits CrazyDrill Flexpilot, CrazyDrill Pilot SST-Inox and CrazyDrill Flex, Mikron Tool has defined a fast and process-reliable procedure which achieves optimum drilling results.

Deep hole drilling of up to 50 x d (instead of gun drilling):

  1. Pilot drilling (in one drilling stroke)
  2. Deep hole drilling in several drilling steps (deep hole drilling cycle with chip breaking and chip removal)

Drilling processing according to DIN 66025 / PAL

G83 deep hole drilling cycle with chip breaking and chip removal
Q = depth of the respective drilling step 

1. Pilot drilling:




2. First drilling step Q1 with CrazyDrill Flex SST-Inox / CrazyDrill Flex Steel / Titanium up to maximum drilling depth of Q1 in one step (see cutting data table), with subsequent chip removal


3. Further drilling steps Qx as per in cutting data table, respectively, with subsequent chip removal

MikronTool-Products-Process-Drilling-depth-Q1-Qx-more-pilot drill


Between the drilling steps, the drill may exit completely from the bore. Do not take the drill completely out from the bore in case of resonant vibration. After the drill reached desired cutting depth, return at increased feed rate (or in case of perfect conditions rapid traverse) to safety position.

Tested and approved

Mikron Tool has determined the ideal cutting parameters (drilling speed to tool life ratio and process reliability) when using CrazyDrill Flexpilot, CrazyDrill Pilot SST-Inox and CrazyDrill Flex. These are listed in the cutting data tables according to drill diameter, drilling depth and material to be machined. The detailed cutting data tested by Mikron Tool, such as cutting speed vc, feed rate f and drilling impact Q, permit a quick and secure machining.

The overview of the cutting values table according to material group, material type, hardness degree and tensile strength, material number, DIN and AISI/ASTM/UNS permits quick determination of the parameters to be used.


An impact-resistant and user-friendly drill packaging is absolutely necessary for CrazyDrill Flex. Mikron Tool offers all tools of the CrazyDrill Flex family in a high quality, single package.

Notes or further questions

You can find indications about tool holders, cooling and lubrication under the column "Additional Tech Specs".

Mikron Tool has an international team of cutting technology experts who  are pleased to answer your questions (how to use a drill, tools, machines, tool holders, cooling, machining process…).

Use this link to contact us directly.