The clamping of tool holder is the clamping force of holder working on the tool, which can be measured by Nm (Newton meter). The higher Nm is the tighter clamping is to hold the tool, furthermore, the rigidity of holder is good for not slipping or loosing under harsher conditions that is also known as "tool dropping".In other words we should choose the right tool holder with enough clamping force according to different cutting conditions to ensure processing quality or extend the life of tool and machine spindles.
The importance of clamping force
Protect the life of the machine spindle
If the clamping force is not applied strong enough, the harsher conditions are the more vibrations are caused. Such vibration will severely damage the front-end bearing of spindle, significantly reduce the bearing life and affect the accuracy of spindle. Many spindle bearings end their life early due to no enough clamping force applying, it costs thousands maintenance fees and makes great loss for suspend operation.
Meet the standard of the surface roughness and machining accuracy
Under the same condition of accuracy, the inadequate clamping of tool holder applying to workpiece will cause bad surface roughness or less accuracy. In the worst case it will cause "tool dropping" or eternal damage due to less clamping and Z axle size changed.
Protecting and Extending Tool Life
Under the same condition of accuracy, the inadequate clamping of tool holder applying to tool will cause vibration following by abnormal and accelerated wear. In the worst case it will cause the entire tool to be scrapped. The clamping of holder is various the ways of holding, for example force the clamping of type PFK's collet on one side with 4 angular degree is much higher than the type ER's collet on one side with 8 angular degree. Even the same tool holders have different clamping forces because of different manufacturers, productions and know-how. For example, the PARFAITE's hydraulic handle which inner diameter is 20mm, clamping force is higher than other brands about 40%. PARFAITE sincerely propose to purchase a tool holder with sufficient clamping force, besides, the customers should buy handle with tolerance above h6 to ensure the proper clamping force applied and maintained.