The Crown Midi Revolution hollowing tool.
Overall length 575 mm Handle 355 mm
The Midi Revolution Hollowing Tool from Crown is excellent for the hollowing of hollow forms, goblets and boxes. The supplied "Super Ring" cutter features an adjustable brass limiter, which acts as a chip breaker, limiting the depth of cut. In practice adjusting the angle at which the tool is presented to the work can also vary the depth of cut. This is a very easy-to-use tool requiring little practice to master the techniques involved and can leave a great finish requiring minimal sanding. A shaped scraper cutter is also supplied should the surface require further refinement. Both the cutters are produced from cryogenically treated steel for excellent edge retention.
It has long been understood that by subjecting metal tools to elevated temperatures and then rapidly cooling them, the properties of the metal can be altered. This happens because the crystal structure of the metal is altered to change the way the metal reacts when in use.
The two main crystals in tooling steel are the larger and softer austenite and a smaller, more stable martensite. Through heat treatment, we look to transform the austenite to martensite to produce steel with good wear characteristics and an amount of ductile properties.
When combined with good quality heat treatment, the cryogenic process greatly enhances the austenic transformation. Also at these extreme temperatures of -301F (-185C), fine 'eta' carbides are formed within the carbon structure. Growing very slowly and only at theses very low temperatures, 'eta' carbides are extremely small and act as a 'filler' between the other crystals in the metal.
The combined effect of cryogenic processing is to produce a refined crystal structure in your hand tool that will give years of service by producing a blade that will retain its edge longer and give a superior performance 'feel' in use over standard HSS tools.
Q Will my blade need re-
A No, cryogenics is a once only, through tool treatment
Q Couldn’t I get the same effect by ‘dipping’ my blade in Nitrogen?
A No, you will produce thermal shock in the tool making it unstable. We use a sealed chamber that is computer controlled to give repeatable quality levels. The process takes several days to complete.
Q What happens when I re-
A Use a gently sharpening motion with plenty of coolant, that way you will need to remove less worn tool than before to produce a perfect edge.