Given the same shape, size and grade, the chipbreaker is often the difference between a clean operation and a broken edge. It is the moulded groove on the rake face that curls and breaks the chip. This page explains how to read it and how to choose.<\/p>\n
A chip leaving the cutting edge wants to form a long ribbon. The chipbreaker groove forces it to curl tightly; the tighter the curl, the higher the stress in the chip, and past a certain point it snaps. Whether it snaps depends on three things: the groove shape, the feed, and the depth of cut.<\/p>\n
So the chipbreaker sets the usable feed window<\/em> of the insert. Every manufacturer publishes that window per chipbreaker; the per-model pages on this site list the actual feed range for each SKU.<\/p>\n In The 60 most common geometries in our catalogue, by intended duty:<\/p>\n The most common field error is choosing a roughing chipbreaker because the depth of cut is large, then running it at finishing feed. The result is a long stringy chip, poor surface, and eventual edge breakage. The reverse error \u2014 a finishing breaker at roughing feed \u2014 snaps the edge immediately.<\/p>\n Practical approach:<\/p>\n This is separate from the chipbreaker, but it is chosen at the same time.<\/p>\nReading the code<\/h2>\n
CNMG 120408-PM<\/code>, the PM<\/code> after the dash is the chipbreaker. There is no universal standard, but the convention across most of the ranges we stock is:<\/p>\n\n
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\n \n\u69fd\u578b<\/th>\n Seen on<\/th>\n Duty<\/th>\n<\/tr>\n<\/thead>\n \n PB1<\/strong><\/td>\n 423 insert records<\/td>\n \u7cbe\u52a0\u5de5 \u2013 light feed, steel and stainless<\/td>\n<\/tr>\n \n PC2<\/strong><\/td>\n 381 insert records<\/td>\n \u4e2d\u52a0\u5de5 \u2013 general steel and stainless<\/td>\n<\/tr>\n \n KC2<\/strong><\/td>\n 350 insert records<\/td>\n \u4e2d\u52a0\u5de5 \u2013 cast iron and steel<\/td>\n<\/tr>\n \n MM4<\/strong><\/td>\n 294 insert records<\/td>\n \u4e2d\u52a0\u5de5 \u2013 milling, multi-material<\/td>\n<\/tr>\n \n MC3<\/strong><\/td>\n 180 insert records<\/td>\n \u4e2d\u52a0\u5de5 \u2013 stainless and superalloys<\/td>\n<\/tr>\n \n F<\/strong><\/td>\n 170 insert records<\/td>\n \u7cbe\u52a0\u5de5 \u2013 sharp, very low feed<\/td>\n<\/tr>\n \n MM3<\/strong><\/td>\n 160 insert records<\/td>\n \u4e2d\u52a0\u5de5\/semi-finish \u2013 milling<\/td>\n<\/tr>\n \n KD5<\/strong><\/td>\n 137 insert records<\/td>\n Heavy roughing \u2013 cast iron<\/td>\n<\/tr>\n \n MC4<\/strong><\/td>\n 125 insert records<\/td>\n \u4e2d\u52a0\u5de5\/rough \u2013 stainless and superalloys<\/td>\n<\/tr>\n \n PA1<\/strong><\/td>\n 119 insert records<\/td>\n \u7cbe\u52a0\u5de5 \u2013 steel, low feed<\/td>\n<\/tr>\n \n KC4<\/strong><\/td>\n 112 insert records<\/td>\n \u7c97\u52a0\u5de5 \u2013 cast iron<\/td>\n<\/tr>\n \n PC4<\/strong><\/td>\n 112 insert records<\/td>\n \u4e2d\u52a0\u5de5\/rough \u2013 steel<\/td>\n<\/tr>\n \n M<\/strong><\/td>\n 111 insert records<\/td>\n \u4e2d\u52a0\u5de5 \u2013 general purpose<\/td>\n<\/tr>\n \n PD8<\/strong><\/td>\n 110 insert records<\/td>\n \u7c97\u52a0\u5de5 \u2013 steel, deep cut<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n Match the breaker to the feed, not the depth<\/h2>\n
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Positive versus negative geometry<\/h2>\n