Accurate and efficient milling with CrazyMill Cool Ball Z4

Product summarize

The newly designed, through-shaft cooled finishing cutter sets new standards in copy and side milling in terms of cutting speeds, performance, tool life and surface quality. It combines HSC (high-speed cutting) and HPC (high-performance cutting), thus becoming an HSPC (high-speed performance cutting) milling tool.

The selected tungsten carbide, geometry, coating and especially through-shaft coolant supply, which ensures perfect cooling of the cutting edges and removes the chips cleanly from the work area, support high cutting speeds, high depth feed ap (up to 4 x d) and high feed rates.

Five versions of ball micro-milling tools with four teeth are available in diameters of 1 – 8 mm (.039” - .315”, fractional inches available): a short one for maximum milling depths of up to 2 x d, a medium one of up to 3 x d and a long one of up to 5 x d; the cutting length of these ball micro-milling tools is of 2 x d. Additionally, two more versions with a progressive flute-angle have a maximum milling depth of up to 3.5 x d (Type M) and of up to 4.5 x d (Type N), in these cases the cutting length is corresponding to the respective milling depth.

The milling process with CrazyMill Cool Ball Z4

Climb milling and conventional milling

Mikron Tool recommends climb milling for the machining of surfaces or edges. Here the chip thickness is greater at the beginning and decreases continuously, the cutting forces remain low. With conventional milling, however, high cutting forces would push the milling tool away from the part. Thus surface quality decreases.



Mikron Tool recommends vertical machining with respect to the workpiece for semi-finishing with CrazyMill Cool Ball (machining angle 0°) or a machining angle of 15° or 75° with respect to the workpiece surface.

Recommended cutting parameters

vc and fz = as specified in the cutting data table
End mill Type A, B and M:                         ap = max. 1 x d,      ae = 0.2 x d
End mill Type C and N:                             ap = 0.5 x d,           ae = 0.2 x d




Mikron Tool recommends machining at a machining angle of 15° or 75° with respect to the workpiece surface for finishing with CrazyMill Cool Ball. This shifts the milling contact away from the tool’s axis center towards its external diameter, where the ideal cutting geometry takes effect and also the cutting speed increases (the cutting speed is zero at the tool’s center).

An angle of 15° of the milling body with respect to the workpiece brings certain advantages:

  • The cutting speed is higher
  • Better surface quality
  • Longer tool life

Recommended cutting parameters

vc and fz = as specified in the cutting data table
ap = 0.1 x d
ae = 0.05 – 0.1 x d depending on the required surface quality
ae = fz for maximum surface quality



For side-finishing with CrazyMill Cool, the machining must be executed vertically with respect to the workpiece (machining angle 0°). 

Recommended cutting parameters

vc and fz = as specified in the cutting data table
End mill Type M:                                       ap = 3 x d,              ae = 0.02 – 0.1 x d
End mill Type N:                                       ap = 4 x d,              ae = 0.02 – 0.1 x d


Tested and approved

Mikron Tool has determined the ideal cutting parameters (ratio of tool life to process reliability) for the use of CrazyMill Cool. These are listed in the cutting data charts for the milling tool's diameter, milling tool type and type of machining (copy, side milling) as well as the material to be machined. Unique cutting data tested at Mikron Tool such as cutting speed vc, feed per tooth fz and cutting depth ap or cutting width ae ensure quick and safe machining.

The cutting data chart overview for material group, type of material, degree of hardness or tensile strength, material number, DIN and AISI/ASTM/UNS ensure a quick determination of the cutting data to be used.


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

Notes or further questions

Please find more information about tool holders, cooling or lubrication under “Additional Info”.

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.