The cutting tool can vary according with the type of cutting method used.
Basically we have 5 kinds of methods and blades :
- Fast Cutting off ( friction by melting material ) = the cut is basically made by melting the tube , normally are used Cr-V circular blades . It is a NON precision cutting off method and also leave a lot of burrs on the cut edges of tubes . Saw blades have pretty short life time , and it is not available for any coating of wear resistant materials . It is a re-sharpable blade
- Slow Cutting off ( by removal of material ) = this cutting method is practically almost totally replacing the friction type on existing machines , whilst on new machines is anymore applied . HSS ( High Speed Steel ) circular saw blades are used . DMo5 steel grades . On these kind of steel blades it is possible apply a wide range of wear resistant coatings . These are precision cutting off and they leave a clean cut of tube edges .
HSS blades life time is longer respect friction type and they are also re-sharpable .
- Slow Cutting off TCT ( by removal of material ) with circular saw blades having carbide inserts brazed on teeth . TCT ( Tungsten Carbide Teeth ) = this is the latest technology available for tube cutting off in line . It has the same features of HSS with the peculiarity that life time is much longer respect common basic HSS blades ( till 6 , 8 times ) . They are also wear resistant coated , but they are NOT re-sharpable .
The operative concept of this technology is , since the extra costs coming by stopping tube mills to replace the cutting blade are so heavy , we try to stop it as much lesser as we can due to cutting tools . The extra higher cost of these blades is compensated by cost savings coming from less line stops and tube scraps while stopping and re-starting it .
It is a blades VERY delicate to be used that need certain care and skilful operators
- Guillotine cutting off = this method is not so popular in Europe and in any case is mostly used to cut Stainless Steel tubes . Its advantage is that these machines( Alpha or Beta type) are pretty much shorter , compact respect conventional flying cut of machines using circular saw blades till 1/6 . Cutting speed is faster . The length of the tube mill hence is shorter . Main problem by using this cut is the deformation of the ends of tubes , partially limited by using the horizontal scarfer .