“Kodawari” – Tecnara’s Philosophy


Tencara Tooling Systems is proud to offer toolholder that meet the highest standard in the industry.  Since the inception of our company in 1979, our products have been manufactured in accordance with the Japanese principal of Kodawari, which means purposeful, unswerving progress.  Each of our gage quality toolholders is built in line with this principal of total dedication to continuous improvement.


During the manufacturing process, the toolholderis subject to distortion from the high-temperature case-hardening process.  This distortion makes it necessary to reestablish exact datum centers to positon toolholders precisely for taper grinding.  To set up this stage, which is the most important in terms of ultimate concentricity, we grind 60 degree chamfers at the precise rotating center.  The precise positioning and repeatability of these chamfers ensure that all Tecnara toolholders meet the most exacting specification of symmetry and concentricity.


The most common measurement of taper shank accuracy are the International Cone Tolerance Systems specifications.  Using this system, cone accuracy specifications are classified by AT grade – a measurement of linear accuracy.  Tecnara uses taper area contact specifications as well, because high precision work requires absolute 360 degree engagement for the entire taper length between the shank and the machine spindle.  This high precision geometry is essential if the machine’s accuracy and rigidity are to be consistent throughout the cutting process.


We use very careful and time consuming traverse grinding with minimal pressure to meet above mentioned two taper specifications and ensure that every toolholder meets these high standards.  Although our traverse grinding is a slow and expensive procedure, it is far more effective in avoiding distortion of toolholders and possibility of egg-shaped taper shanks, which are very common for toolholders manufactured by inappropriate grinding process.  Unfortunately, with other methods, it is virtually impossible to achieve a taper accuracy within .000040” roundness and a 90% or better taper contact and ensure that every toolholder meets these high standards.


To make the best toolholders, one must use the best equipment.  To ensure absolute consistency, an experienced factory technicians uses taper gages to check taper shank accuracy throughout the grinding and inspection process.  The taper gages used by Tecnara are the best in the world  They are manufactured by Japan’s most prestigious gage manufacture, and they are used by the leading Japanese machine manufacturers.