Shrink coupling heating has been a well-known technique in the field of permanent couplings since antiquity. Today it’s finally available on the reversible blocking system market of cylindrical stem cutting tools on high speed work toolholder. To obtain effective and safe blocking, reducing to the minimum the expansion time of the toolholder is necessary. The inductive heating with high-energy field allows one to exchange the tools in just a few seconds. This blocking system guarantees extraordinary performance in high-speed manufacturing, where high values of concentricity and coupling tightening are required. The blocking of the tool in the spindle is based on the volumetric variation of steel’s molecular structure regarding temperature. The increase in temperature determines a proportional increase in the internal diameter of the spindle, which allows the insertion of the cylindrical stem tool. After cooling, the spindle will return to its original size, creating high radial blocking strength over the entire contact surface. If the deformation is included in the material’s elasticity field of which the spindle is made up, the process can theoretically be repeated endlessly. The fundamental factors that regulate this process are: the heating time, resulting temperature and the flow of thermal energy that crosses the spindle. Thanks to the localized electromagnetic field, the desired expansion in the spindle’s

blocking area is quickly obtained while transferring very little energy to the toolholder. Correct induction times and the precise location of the electromagnetic field significantly reduce the heat propagation in the spindle, with resulting contained tool heating with respect to the traditional hot-air systems. The greater temperature

difference between spindle and tool allows easier disassembly of the tool. With the use of the induction machines and Grip plus by Mickros CT - CTF and CTP spindles, mounting and dismantling shrink tools in quick super steel and hard metal is possible. Thanks to the spindle’s short heating phase the tool doesn’t have the

time to heat up, allowing extraction also in the event of coefficient thermal expansion the same as that of the spindle. Using heat resistant rimmed steel and thanks the application of sophisticated thermal treatments, the toolbox spindle keeps its precise characteristics and elasticity even after many cycles. The maximum temperatures registered during the heating are somewhere around 300°C-340°C; these are much lower than the temperatures that could produce a structural change in the material. 

This is why our slogan is “PRECISION IN TIME”.

• Quick insertion and extraction of the tool
• Increased radial blocking strenght
• No tools magnetization
• Long lasting tool and great performances
• Excellent surface finish of worked material
• Great flexional and radial rigidity
• Reduced size of the spindle and compact outline (profile)
• Hard metal and quick steel with shank tolerance h6
• Long life spindle and firmness shape toolholders
• Concentricity values in the spindle-tool coupling lower than 3 micron
• All toolholders have a subtle balancing in G 2,5 from stock.