Cuttermasters Handbook on End Mills and End Mill Geometry, CM-BEM

Cuttermasters Handbook on End Mills and End Mill Geometry, CM-BEM

Preface This book contains general information about end mills and basic information on sharpening, and use of these tools. We also provide basic information about grinding wheels and tool coatings which are becoming more sophisticated as materials and processes evolve. Keeping set up and run maintenance down time to a minimum is good, but destroying and throwing out good tools is a waste of money. Production job shops seldom effectively use regrinds because of some legacy issues” Part cycle time and pressure to keep things moving always steal the show. Carbide tools will run many useful cycles depending on the tool and how they are used. HSS and Carbide each present unique regrind opportunities. The Cuttermaster Professional has been designed to meet the demands presented by the use of advanced materials and geometries. End mills are one of the most overused tools in the machine shop. In an industry where part cycle time is perceived as the defining measure of success or failure on a job, this tool is commonly run until the material has failed. Fact is in today’s world where carbide is prevalent new rules apply. As the Story goes there’s no such thing as a sharp piece of carbide. Or at least nothing that will stay sharp after more than one or two revs in the machine. Carbide is brittle. It’s powdered metal, ferchrissakes. And if you grind it razor sharp, the edges will fail and propagate micro fractures into the flute. This includes the corners (reason we invented on corner radius hand hone). The only good edge on a carbide cutting tool (and on any tool, actually; but carbide is most sensitive), is an edge that’s honed or polished slightly – predulled so that it doesn’t have any sharp corners or fragile edges. If you regrind a tool be mindful of the original geometry, edge prep and tool symmetry. Even the hardest materials fail when subjected to high stresses. Finally; in-house sharpening and tool modification capability is a major competitive improvement for any shop. To cut an order for a $5 sharpening job is a loosing proposition, v.s. if the machinist can sharpen his or her own tool on spec, then the project is under the control of the operator. This was not possible until machines evolved to a point where anyone in the shop can grind a perfect tool without years of tool grinding experience. The Cuttemaster Professional Tool Room Series is designed to be used on the shop floor or by tool room staff with little training or other investment. We thank everyone who has contributed material directly or indirectly to this project. It is our intention to have a positive impact on the bottom line.