Measures to eliminate machining faults of end mill

Fault	Occurrence situation	Measures
Tools breaking (when using solid small -diameter and brazing small-diameter end mill)	●When the tools cuts in a work piece ●When the tools is pulled out	●Reduce feed ●Reduce overhanging volume ●Shorten the cutting edge length to the minimum limit of necessary length
	●When the tool is machining normally	●Reduce feed ●Wear control → replace tools as early as possible ●Replace fixture or spring collet ●Reduce overhanging volume of the tools ● Make passivation treatment to the tools ●If using 4-flute end mill, change it to 3-flute or double-flute mill (prevent chip jamming) ●Change dry milling to wet milling (using cutting fluid). When wet milling supplies the fluid from front, change it to be supplying from back or cross upper side. The flow of cooling fluid shall be sufficient
	●When feed direction changes	●Use arc interpolation (NC machine tool), or halt ●Reduce the feed before and after direction change ●Replace fixture or spring collet
Chipping	●Chipping at tools point	●Use manual regrinding to chamfer at corner part ●Change climb milling to conventional milling
	●Damage in cutting depth interface	● Change climb milling to conventional milling ●Reduce milling speed
	●Chipping is distributed in central part or in the whole cutting edge	●Make passivation chamfering or enlarge chamfering ●Change rotation of spindle (when the machine tool is vibrating) ●Increase milling speed ●When there is friction sound during milling, increase feed ●If applying dry milling, change it to wet milling or use air to cool ● Replace fixture or spring collet ●Reduce cutting speed
	●Large chipping of cutting edge	●Reduce feed ●If using 4-flute end mill, change it to 3-flute or double-flute end mill ●Make passivation chamfering or enlarge chamfering ●Replace fixture or spring collet [when using solid end mill] ●Reduce milling speed ●If applying dry milling, change it to wet milling. When wet milling supplies the fluid from front, change it to be supplying from cross upper side or back. The flow of cooling fluid shall be sufficient.[when using brazing end mill] ●If applying wet milling, change it to dry milling, using compressed air. When air is supplied from front, change it to be supplying from back or cross upper side. Its flow shall be sufficient ●In steel's slot milling, with standard cutting condition as target value, select appropriate milling speed (at low milling speed……It will produce low speed damage, and pressing object will split and be damaged.) (at high milling speed ……Chips will jammed and it will produce thermal cracking while milling deep slot
Early wear of tools		●Reduce milling speed ●If it is conventional milling, change it to climb milling ●Increase feed ●Adopting wet or compressed air cooling milling ●If using regrinding end mill, improve roughness of back

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