Accurate and quick
centering and chamfering

The CrazyDrill Twicenter center drill offers the basis for a high-precision borehole. The sturdy  design of the tool and its precision ensure the highest degree of position accuracy during center drilling and the highest degree of orthogonality and alignment accuracy (straightness) for the follow-up drill (all types of drill bits in tungsten carbide).

The use of a centering tool in rough or irregular surfaces makes sense even in tools with high a degree of self-centering capability such as CrazyDrill SST-Inox. A considerably higher degree of position accuracy and orthogonality can be achieved here with CrazyDrill Twicenter. In addition, using CrazyDrill Twicenter on surface-hardened materials is recommended. The use of the center drill with through-tool cooling and high-performance coating can translate to significantly longer life for the follow-up drill. 60°, 90° or 120° chamfering of the borehole can be done in the same processing step.

If pilot drilling with cylindrical guidance is needed, we recommend the pilot drill CrazyDrill Pilot or CrazyDrill Flexpilot.

When drilling on inclined, convex or concave surfaces we recommend CrazyDrill Crosspilot as the centering drill/pilot drill.

Hole quality and stable machining processes (no jamming, no damage to the cutting edges of the follow-up drill) are guaranteed in drill bits for metal such as the CrazyDrill family by the use of matching tool tolerances and tip angles.

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 even when using smallest drill bits. 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 CrazyDrill Twicenter, Mikron Tool has defined a fast and reliable procedure which achieves optimal drilling results.

Center drilling and chamfering in one step with CrazyDrill Twicenter

1. CrazyDrill Twicenter

• Determine the desired cutting depth according to drilling diameter and chamfer angle or chamfer width (see tables below)
• Activate internal or external cooling
• Go down at drilling speed and feed rate (see cutting data) and drill in one step  

• After the drill reached the desired cutting depth, return at feed rate or rapid traverse

 Tables for cutting depths

For 60° chamfer angle/130° tip angle:

For 90° chamfer angle/130° tip angle:

Mikron Tool has determined the ideal cutting parameters (drilling speed to tool life ratio and process reliability) when using CrazyDrill Twicenter. 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 Twicenter. Mikron Tool offers all tools of the CrazyDrill Twicenter family in a high quality, single package.

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.