Although almost any book and/or text on metal cutting, cutting tool design, and# j9 {+ D0 c( Q: i+ w5 g: S manufacturing process discusses to a certain extent the tool geometry, the body of + e. H. V% {' R, X* tknowledge on the subject is scattered and confusing. Moreover, there is no clear. K- ?- l$ m4 q9 M* o% r objective(s) set in the selection of the tool geometry parameters so that an answer6 p4 b+ C6 f, W2 |, z% i( ]0 k to a simple question about optimal tool geometry cannot be found in the literature g' H M" S1 V# I- o' r' S0 don the subject. This is because a criterion (criteria) of optimization is not clear, on1 j- l2 Z" \; ? one hand, and because the role of cutting tool geometry in machining process ; H. r6 e" ]( g7 ~optimization has never been studied systematically, on the other. As a result, many 0 O% L4 W6 {3 hpractical tool/process designers are forced to use extremely vague ranges of tool 0 t' U/ d9 f: x, m$ s) Q+ y% d7 [geometry parameters provided by handbooks. Being at least 20+ years outdated, ' a; A. P6 ?' p4 a: |- hthese data do not account for any particularities of a machining operation including " E0 U8 q S3 _ b/ _+ \( p: a! _: \a particular grade of tool material, the condition of the machine used, the cutting % }+ ^7 B5 s0 R/ b: ^# yfluid, properties and metallurgical condition of the work material, requirements to* [, _$ t0 ]+ M& D. K M/ X \ the integrity of the machined surface, etc. 1 j5 h; a, P9 e2 y' EUnfortunately, while today's professionals, practitioners, and students are . u9 l7 v1 X5 W" a1 H$ l) linterested in cutting tool geometry, they are doomed to struggle with the confusing) J- ~. {2 n. D( E* k9 O7 ? terminology. When one does not know what the words (terms) mean, it is easy to" U. v7 ~; ]$ Q+ X$ o slip into thinking that the matter is difficult, when actually the ideas are simple,' M- O2 n& H: D3 G5 m/ v5 K easy to grasp, and fun to consider. It is the terms that get in the way, that stand as a $ L! R3 t' f0 {/ p4 T- ywall between many practitioners and science. This books attempts to turn those* m5 e! r% V) H. _ F walls into windows, so that readers can peer in and join in the fun of proper tool / |4 A% r: g @% j: zdesign.3 g. {% g( `6 w. ^ So, why am I writing this book? There are a few reasons, but first and foremost, 4 c6 F4 [1 r) D& S4 ~# r$ N1 @because I am a true believer in what we call technical literacy. I believe that Q& i6 R2 ~- |) F2 T5 Xeveryone involved in the metal cutting business should understand the essence and! S. V8 \% j" X" J0 R% {7 F importance of cutting tool geometry. In my opinion, this understanding is key to" A2 G( o' p5 B$ l. ~- u" s improving efficiency of practically all machining operations. For the first time, this6 i5 f) Y( u# E: c book presents and explains the direct correlations between tool geometry and tool ' ~) F! o) p5 q' G2 Fperformance. The second reason is that I felt that there is no comprehensive book4 I, u) @- `* V7 @: t7 v+ V on the subject so professionals, practitioners, and students do not have a text from 6 _6 _& o# H2 Y- b X* x4 O1 Lwhich to learn more on the subject and thus appreciate the real value of tool" {( u$ {/ x, B5 R5 f# g geometry. Finally, I wanted to share the key elements of tool geometry that I felt 2 T% B$ ^: q3 Q( a" Lwere not broadly understood and thus used in the tool design practice and in/ ~% O, G/ F9 L9 ]% @% S f optimization of machining operations in industry. Moreover, being directly 2 o1 D* C* ] I: H4 E8 Iinvolved in the launch of many modern manufacturing facilities equipped with ! h; H' f- g7 m0 t% a# K! M1 Hstate-of-the-art high-precision machines, I found that the cutting tool industry is not2 I$ t- R. V# h: Z" `" y ready to meet the challenge of modern metal cutting applications. One of the key5 _: J+ r# o s9 v7 c! Y+ g, i1 F issues is the definite lack of understanding of the basics of tool geometry of* k& B" G; x i& y$ ^) N$ J' o standard and application-specific tools.' c2 e; o' ?1 b$ c- l The lack of information on cutting tool geometry and its influence on the0 p$ y. B' P+ `; v outcome of machining operations can be explained as follows. Many great findings. @8 [! x$ N6 G5 I+ t on tool geometry were published a long time ago when neither CNC grinding2 F2 N; g- W: L6 L# V" G machines capable of reproducing any kind of tool geometry were available nor7 @0 l7 b+ [6 W) X were computers to calculate parameters of such geometry (using numerical* A. c8 _$ e) \: | methods) common. Manual grinding using standard 2- and 3-axis simple grinding' d7 Q6 O1 [4 x% U2 A features was common so the major requirement for tool geometry was the simpler 8 o+ n% u, m5 [+ V% Jthe better. Moreover, old, insufficiently rigid machines, aged tool holders and part 3 m1 J) Q* {) A: M1 Y' Nfixtures, and poor metal working fluid (MWF) selection and maintenance levered 4 V2 q4 F6 ?* D' u sany advancement in tool geometry as its influence could not be distinguished under 5 x2 b( s$ s: a" b" [these conditions. Besides, a great scatter in the properties of tool materials in the 6 Y( c' A; y0 T/ T, Q/ d5 r7 U5 ^past did not allow distinguishing of the true influence of tool geometry. As a result,) W8 @+ ]8 p1 g$ a1 c studies on tool geometry were reduced to theoretical considerations of features of 9 A0 ? F" u: K. ]1 n' H Ptwist drills and some gear manufacturing tools such as hobs, shaving cutters, 2 G r+ S/ }, N, o+ Sshapers, etc.5 J& Y& g8 R5 B Gradually, once mighty chapters on tool geometry in metal cutting and tool/ I$ |: W) i! T) [3 g design books were reduced to sections of few pages where no correlation between 2 X4 P3 A; c) l8 u7 x9 F: Btool geometry and tool performance is normally considered. What is left is a7 F& C% p6 j% g6 H2 G0 R general perception that the so-called “positive geometry” is somehow better than4 I' H+ {8 ~. Q “negative geometry.” As such, there is no quantitative translation of the word6 N- ?' t* z( v8 c “better” into the language of technical data although a great number of articles 0 {* X9 J4 e6 _0 Jwritten in many professional magazines discuss the qualitative advantages of# e: Y4 G# w7 g “positive geometry.” For example, one popular manufacturing magazine article- P, e9 R2 h, w read “Negative rake tools have a much stronger leading edge and tend to push! f; L' K$ o4 H8 G+ o% R against the workpiece in the direction of the cutter feed. This geometry is less free ) d2 Y# }: T9 [8 }. ccutting than positive rakes and so consumes more horsepower to cut.” Reading 9 R7 y! T4 C% T' C: kthese articles one may wonder why cutting tool manufacturers did not switch their 0 r, e9 l/ Z6 ?4 utool designs completely to this mysterious “positive geometry” or why some of ( l. z) n1 |- G1 ~( ~* I- r0 rthem still investigate and promote negative geometry.( r# y, v( T! W2 E: p1 S+ [ During recent decades, the metalworking industry underwent several important, D! o1 j2 f( W+ z changes that should bring cutting tool geometry into the forefront of tool design 0 |& \8 ~% p4 p# Q6 I xand implementation: |