Rigid threading tool offers superior accuracy and finishing
Sandvik Coromant has introduced a new family of rigid high precision threading tools for the oil, gas and mechanical engineering industries: CoroThread 266.
CoroThread 266's threading stability is achieved with a new design of iLock insert locking interface that keeps the insert rigid, maintaining the correct threading profile and thereby reducing out-of-specification product rejection.
The insert has a slot for each of its three indexible cutting edges. One of the three slots is located on a raised guide rail on the interface of the shim, making it impossible to misfit the insert or for it to move. This guide rail locks the insert into its correct position in the pocket, giving repeatable accuracy with each threading pass. Correct fitting and precise indexing can be achieved by touch alone. The CoroThread 266 insert sits only on the guide rail, and is secured by screwing it into place.
266 is ultra-stable; its rigidity produces threads with less vibration for a good surface finish. Customer tests show threaded products can be made with fewer passes, reducing machine time and increasing productivity.
Indexability of the insert, the E-tolerance, is 0.01mm in the axial direction and 0.05mm radially. This allows a new insert edge to continue cutting with the same accuracy as the previous edge for improved product consistency. With the CoroThread 266, cutting loads on the insert are dispersed without pressure points, allowing the insert and holder to maintain their design integrity. This leads to extended tool and holder life, less downtime for tool changes and greater continuity of production. 
In the oil and gas component industry, tests show indexing accuracy to be 0.01mm change in axial position. Tough Iconel 718 material was used for a threaded component test. The operator was unable to complete the thread on one edge, but indexing a new CoroThread 266 insert edge enabled the work to be finished to the correct diameter in seven additional passes, a total of 27 passes to
complete the product instead of 40 passes with less rigid clamping.
Comparative tests with earlier inserts show visible vibration chatter on the component thread after using four to five components. These inserts, with less stable clamping, had a normal life of 30 components per edge. CoroThread 266 inserts achieved 50 components per edge without vibration chatter, providing a cleaner and better surface.
Overall, tests demonstrate that CoroThread 266 rigid clamping threading leads to increased cutting data and/or longer tool life leading to higher productivity.
