In finish hard turning it is vital to reach the required surface roughness tolerances, since it is the final operation before assembly. The most common way to increase productivity in hard turning is to use a wiper insert. A wiper insert will allow you to increase the feed rate, while maintaining low surface roughness values, and reaching long tool lives.
For a wiper to work properly, there are two criteria:
- The surface has to be straight
- A specific approach angle is needed
For a CNGA-insert, the approach angle
k should be 95
o. On a straight surface (a) the wiper works. If the workpiece is tapered (b), the wiper will not work, since the approach angle is less than 95
o. When machining a curved surface (c), the approach angle changes depending on where you cut, and the wiper will not work.
As long as the machined surface is straight, a wiper can be added to the insert to fit the actual approach angle. In the following case, machining of an inner diameter on a large gear, the approach angle was 15 degrees.
When machining straight surfaces, a wiper insert should always be the first choice, and after our visit, we proposed to use a wiper insert. In this case, the customer requested that the first test was to be done at the existing cutting data, and tool life was significantly improved.
By adding a wiper, the tool life was increased significantly, and using higher feed rate also improved productivity.
For more information, please contact your local Seco representative, or our Advanced material (PCBN/PCD/CERAMIC) team.
 | Author:
Henrik Sandqvist
Product Specialist SECOMAX PCBN/PCD/CERAMIC
SECO TOOLS Shanghai CO., Ltd. Level 2, Building 8, 456 HongCao Rd., Shanghai 200233, China
Office: +86 21 5426 5849
Mobile: +86 185 1520 6942
e-mail: henrik.sandqvist@secotools.com |
