Requiring close tolerances and high-quality surface finishes, seal-ring grooves are a critical feature on many oil and gas components, yet conventional methods for machining them often suffer from slow production and poor process security.

Moreover, the use of a multiple-operation approach that incorporates both roughing and finishing sequences is time-consuming; and single-point or plunging cutters are prone to vibration. Adding to this machining challenge is the common use of difficult-to-machine materials, such as solid Inconel 718 and cladded Inconel 625.

That said, Sandvik Coromant (www.sandvik.coromant.com) is now offering SpiroGrooving, a trade-marked machining method that uses the company’s CoroBore XL system with a ‘spirograph’ tool-path to create close-tolerance seal-ring grooves.

Moreover, the internal coolant feature of CoroBore XL facilitates the machining of advanced materials, with roughing and finishing carried out in the same operation, significantly reducing machining times.

SpiroGrooving uses a circular ‘spirograph’ tool movement in a taper, to reduce chip thickness and provide a light cutting action that allows the use of an increased feed rate. Furthermore, parts of the insert cutting edge have been designed to achieve interrupted cutting, thereby preventing long chips tangling with the tool and spindle.

Sandvik also provides the appropriate NC-code generator. Full details can be found at the Web site(www.sandvik.coromant.com/en-gb/knowledge/calculators_and_software/spirogrooving/pages/default.aspx).