Ch08

Manufacturing Processes for Engineering Materials, 5th ed.
Kalpakjian • Schmid
© 2008, Pearson Education
ISBN No. 0-13-227271-7
Common Machining Processes
FIGURE 8.1 Some examples of common machining processes.
(c) Slab milling (d) End milling
End mill
Cutter
(b) Cutting off(a) Straight turning
ToolTool

ISBN No. 0-13-227271-7
Orthogonal Cutting
FIGURE 8.2 Schematic illustration of a two-dimensional
cutting process, or orthogonal cutting. (a) Orthogonal cutting
with a well-deﬁned shear plane, also known as the Merchant
model; (b) Orthogonal cutting without a well-deﬁned shear
plane.
Rake angle
Chip
Tool face
V Flank
Relief or
clearance
angle
Shear angle
Shear plane
!
Tool
Shiny surfaceRough surface
Workpiece
to
tc
- +
"
(a)
Chip
Rough
surface
Primary
shear zone Flank
Relief or
clearance
angle
Tool face
Tool
tc
to
V
- +
"
Rake angle
(b)
Rough surface

ISBN No. 0-13-227271-7
Chip Formation
FIGURE 8.3 (a) Schematic illustration of the basic mechanism of chip formation in cutting. (b) Velocity
diagram in the cutting zone.
Shear
plane
Workpiece
d
Chip
Tool
A
C
B
A
C
BO
Rake angle,
(b)
Vc
Vs
V
(a)
(90°- )
(90°- + )
( - )
( - )

ISBN No. 0-13-227271-7
Types of Chips
FIGURE 8.4 Basic types of chips produced in metal cutting and their
micrographs: (a) continuous chip with narrow, straight primary shear zone; (b)
secondary shear zone at the tool-chip interface; (c) continuous chip with built-up
edge; (d) segmented or nonhomogeneous chip; and (e) discontinuous chip. Source:
After M.C. Shaw, P.K.Wright, and S. Kalpakjian.
(e)(d)
(a) (b) (c)
Tool
Workpiece
Primary
shear
zone
Chip
Primary
shear zone
Chip
Tool
Secondary shear zones
BUE
Low
shear
strain
High
shear
strain
FIGURE 8.5 Shiny (burnished) surface
on the tool side of a continuous chip
produced in turning.

ISBN No. 0-13-227271-7
Hardness in Cutting Zone
FIGURE 8.6 (a) Hardness distribution in the cutting zone for 3115 steel. Note that some regions in the built-up
edge are as much as three times harder than the bulk workpiece. (b) Surface ﬁnish in turning 5130 steel with a
built-up edge. (c) Surface ﬁnish on 1018 steel in face milling. Source: Courtesy of Metcut Research Associates, Inc.
(a)
(b)
(c)
474
661
588
492
588
656 604
684
565
432
589
656 567 578
512
704
704 639
655770734
466
587
704
372
306
329
289
325
331
286
289
371 418
383
306
386
261
565
327
361
281
289
410
341
281
308
231
201
251
266
317229
377503544409297
316
230
Workpiece
Built-up
edge
Hardness (HK)
Chip

ISBN No. 0-13-227271-7
Chip Breakers
FIGURE 8.7 (a) Schematic illustration of the action of a chip
breaker. Note that the chip breaker decreases the radius of
curvature of the chip. (b) Chip breaker clamped on the rake face of
a cutting tool. (c) Grooves on the rake face of cutting tools, acting
as chip breakers. Most cutting tools now are inserts with built-in
chip-breaker features.
(a) (b)
Workpiece
Tool
After
Chip
Before
Chip breaker
Rake face
of tool
Tool
Clamp
Chip breaker
(c)
Positive rake
Rake face
0° rakeRadius
FIGURE 8.8 Various chips produced in
turning: (a) tightly curled chip; (b) chip hits
workpiece and breaks; (c) continuous chip
moving radially outward from workpiece; and
(d) chip hits tool shank and breaks off. Source:
After G. Boothroyd. (a) (b) (c) (d)

ISBN No. 0-13-227271-7
Oblique Cutting
FIGURE 8.9 (a) Schematic illustration of cutting with an oblique tool. (b) Top view, showing the
inclination angle, i. (c) Types of chips produced with different inclination angles.
Workpiece
i = 30°
i = 15°
i = 0°
Chip
(a) (b) (c)
i
a
o
Tool
Top view
Workpiece
i
a
o
Tool
Chip
y
z
x
c
t

ISBN No. 0-13-227271-7
Right-Hand Cutting Tool
FIGURE 8.10 (a) Schematic illustration of a right-hand cutting tool for turning. Although these
tools have traditionally been produced from solid tool-steel bars, they are now replaced by inserts
of carbide or other tool materials of various shapes and sizes, as shown in (b).
(a) (b)
End-cutting
edge angle
(ECEA)
Side-rake
angle, + (SR)
Axis
Axis
Cutting edge
Face
Back-rake angle, + (BR)
Nose radius
Flank
Side-relief angle
Side-cutting edge angle (SCEA)
Clearance or end-relief angle
Axis
Shank
Insert
Clamp
Clamp screw
Toolholder
Seat or shim

ISBN No. 0-13-227271-7
Cutting Forces
FIGURE 8.11 (a) Forces acting on a
cutting tool in two-dimensional cutting.
Note that the resultant forces, R, must be
collinear to balance the forces. (b) Force
circle to determine various forces acting
in the cutting zone. Source: After M.E.
Merchant.
Chip
Tool
Workpiece
(a) (b)
Fn
Fc
Fs
Ft
R
F
N
R
Chip
V
V
Tool
Workpiece
Fc
Fs
Ft
F
N
R
Cutting force Friction coefﬁcient
Fc = Rcos(β−α) =
wtoτcos(β−α)
sinφcos(φ+β−α)
µ= tanβ =
Ft +Fc tanα
Fc −Ft tanα

ISBN No. 0-13-227271-7
Cutting Data
FIGURE 8.12 Thrust force as a function of rake
angle and feed in orthogonal cutting of AISI 1112
cold-rolled steel. Note that at high rake angles, the
thrust force is negative. A negative thrust force has
important implications in the design of machine
tools and in controlling the stability of the cutting
process. Source: After S. Kobayashi and E.G.
Thomsen.
! = 5°
10°
15°
20°
25°
30°
35°
40°
0 0.1 0.2 0.3
mm/revmm/rev
800
400
0
2200
(N)
Ft(lb)
200
150
100
50
0
250
0 0.002 0.004 0.006 0.008 0.010 0.012
Feed (in./rev)
ut
(in.-lb/in3 uf /ut
α φ γ µ β Fc (lb) Ft (lb) ×103) us uf (%)
25◦ 20.9◦ 2.55 1.46 56 380 224 320 209 111 35
35 31.6 1.56 1.53 57 254 102 214 112 102 48
40 35.7 1.32 1.54 57 232 71 195 94 101 52
45 41.9 1.06 1.83 62 232 68 195 75 120 62
to = 0.0025 in.; w = 0.475 in.; V = 90 ft/min; tool: high-speed steel.
uf /ut
α V φ γ µ β Fc Ft ut us uf (%)
+10 197 17 3.4 1.05 46 370 273 400 292 108 27
400 19 3.1 1.11 48 360 283 390 266 124 32
642 21.5 2.7 0.95 44 329 217 356 249 107 30
1186 25 2.4 0.81 39 303 168 328 225 103 31
-10 400 16.5 3.9 0.64 33 416 385 450 342 108 24
637 19 3.5 0.58 30 384 326 415 312 103 25
1160 22 3.1 0.51 27 356 263 385 289 96 25
to = 0.037 in.; w = 0.25 in.; tool: cemented carbide.
TABLE 8.1 Data on orthogonal cutting of 4130 steel.
TABLE 8.2 Data on orthogonal cutting of 9445 steel.

ISBN No. 0-13-227271-7
Shear Force & Normal Force
FIGURE 8.13 (a) Shear force and (b) normal force as a function of the area of the shear plane and the
rake angle for 85-15 brass. Note that the shear stress in the shear plane is constant, regardless of the
magnitude of the normal stress, indicating that the normal stress has no effect on the shear ﬂow stress
of the material. Source: After S. Kobayashi and E.G.Thomsen.
= 20° to 40°
800
400
0
= 50,000 psi
0 1 32 4 5 6
0 1 32
1200
320
280
240
200
160
120
80
40
0
mm2
(N)
As (in2 x 10-3)
Fs(lb)
(a)
0 1 32 4 5 6
0 1 32
1200
320
280
240
200
160
120
80
40
0
800
400
As (in2 x 10-3)
mm2
(N)
Ft(lb)
(b)
25
30
35
40
20°

ISBN No. 0-13-227271-7
Shear Stress on Tool Face
FIGURE 8.14 Schematic illustration of the distribution of normal and shear stresses at the tool-chip interface
(rake face). Note that, whereas the normal stress increases continuously toward the tip of the tool, the shear
stress reaches a maximum and remains at that value (a phenomenon known as sticking; see Section 4.4.1).
!
"
Tool face
Sliding
Sticking
Stresses on tool face
Tool tip
Tool
Flank face

ISBN No. 0-13-227271-7
Shear-Angle Relationships
FIGURE 8.15 (a) Comparison of
experimental and theoretical shear-angle
relationships. More recent analytical
studies have resulted in better agreement
with experimental data. (b) Relation
between the shear angle and the friction
angle for various alloys and cutting
speeds. Source: After S. Kobayashi.
50
40
30
20
10
0
230 220 210 0 10 20 30 40 50 60
Lead
Copper
Tin
Eq. (8.21)
Eq. (8.20)
Mild steel
Aluminum
(! - ")
Shearangle,#(deg.)
" = 0
! = 10 30 50 70 (deg.)
µ=0 0.5 1 2
60
40
20
0
#(deg.)
(a) (b)
Merchant [Eq. (8.20)]
Shaffer [Eq. (8.21)]
Mizuno [Eqs. (8.22)-(8.23]
φ = 45◦
+
α
2
−
β
2
φ = 45◦
+α−β
φ = α for α > 15◦
φ = 15◦
for α < 15◦

ISBN No. 0-13-227271-7
Specific Energy
Specific Energy∗
Material W-s/mm3 hp-min/in3
Aluminum alloys 0.4-1.1 0.15-0.4
Cast irons 1.6-5.5 0.6-2.0
Copper alloys 1.4-3.3 0.5-1.2
High-temperature alloys 3.3-8.5 1.2-3.1
Magnesium alloys 0.4-0.6 0.15-0.2
Nickel alloys 4.9-6.8 1.8-2.5
Refractory alloys 3.8-9.6 1.1-3.5
Stainless steels 3.0-5.2 1.1-1.9
Steels 2.7-9.3 1.0-3.4
Titanium alloys 3.0-4.1 1.1-1.5
∗ At drive motor, corrected for 80% efficiency; multiply
the energy by 1.25 for dull tools.
TABLE 8.3 Approximate Specific-Energy Requirements in
Machining Operations

ISBN No. 0-13-227271-7
Temperatures in Cutting
400
500
450
Workpiece
Tool
Chip
30
80
130
380
600
360
500
600
650
700
Temperature (°C)
650
600
FIGURE 8.1 Typical temperature
distribution in the cutting zone. Note the
severe temperature gradients within the
tool and the chip, and that the workpiece is
relatively cool. Source: After G.Vieregge.
200
300
V = 550 ft/min
Work material: AISI 52100
Annealed: 188 HB
Tool material: K3H carbide
Feed: 0.0055 in./rev
(0.14 mm/rev)
0 0.5 1.0 1.5
mm
700
600
500
400
°C
0 .008 .016 .024 .032 .040 .048 .056
Distance from tool tip (in.)
1400
1300
1200
1100
1000
900
800
700
Flanksurfacetemperature(°F)
(a)
550ft/min
3
00
200
2000
1800
1600
1400
1200
1000
800
600
400
Localtemperatureattool-chipinterface(°F)
0 0.2 0.4 0.6 0.8 1.0
Fraction of tool-chip
contact length measured
in the direction of chip flow
1100
900
700
500
300
°C
(b)
FIGURE 8.2 Temperature distribution in turning as a function of cutting speed:
(a) ﬂank temperature; (b) temperature along the tool-chip interface. Note that
the rake-face temperature is higher than that at the ﬂank surface. Source: After
B.T. Chao and K.J.Trigger.
T =
1.2Yf
ρc
3 Vto
K
FIGURE 8.18 Proportion of the heat generated in cutting transferred to the
tool, workpiece, and chip as a function of the cutting speed. Note that most of
the cutting energy is carried away by the chip (in the form of heat), particularly
as speed increases.
W
orkpiece
Cutting speed
Energy(%)
Tool
Chip

ISBN No. 0-13-227271-7
Terminology in Turning
FIGURE 8.19 Terminology used in a turning operation on a lathe, where f is the feed (in mm/rev or in./rev) and
d is the depth of cut. Note that feed in turning is equivalent to the depth of cut in orthogonal cutting (see Fig.
8.2), and the depth of cut in turning is equivalent to the width of cut in orthogonal cutting. See also Fig. 8.42.
Depth of cut
(mm or in.)
Feed
(mm/rev or in./rev)
Tool
Chip

ISBN No. 0-13-227271-7
Tool Wear
FIGURE 8.20 Examples of wear in cutting tools. (a) Flank
wear; (b) crater wear; (c) chipped cutting edge; (d) thermal
cracking on rake face; (e) ﬂank wear and built-up edge; (f)
catastrophic failure (fracture). Source: Courtesy of
Kennametal, Inc.
Flank face
Rake face
Flank wear
Flank face
BUE
Rake face
Crater wear
Flank face
Rake face
Thermal
cracking
(b)
(d)
(c)
(e)
(a)
Rake
face
Crater
wear
depth
(KT)
Flank
wear
Flank
face
Tool
Rake face
Crater
wear
Depth-of-cut line
Nose
radius
R
Flank wear
Depth-of-cut line
VBmax
VB
Flank face
Taylor tool life equation:
VTn
= C
High-speed steels 0.08-0.2
Cast alloys 0.1-0.15
Carbides 0.2-0.5
Ceramics 0.5-0.7
TABLE 8.4 Range of n values for various cutting tools.

ISBN No. 0-13-227271-7
Effect of Workpiece on Tool Life
FIGURE 8.21 Effect of workpiece microstructure on tool life in turning.Tool life is given in terms of the time
(in minutes) required to reach a flank wear land of a specified dimension. (a) Ductile cast iron; (b) steels, with
identical hardness. Note in both figures the rapid decrease in tool life as the cutting speed increases.
Hardness
(HB) Ferrite Pearlite
a. As cast
b. As cast
c. As cast
d. Annealed
e. Annealed
265
215
207
183
170
20%
40
60
97
100
80%
60
40
3
_
50
100 300 500 700 900
100 150 200 250
0
40
80
120
m/min
Cutting speed (ft/min)
Toollife(min)
a
b c
d
e
(a)
Pearlite-ferrite
Martensitic
Sp
heroidized
0.1 0.2 0.3 0.4
m/s
(b)
100
80
60
40
20
0
Toollife(min)
20 30 40 50 60 70 80 90

ISBN No. 0-13-227271-7
Tool-Life Curves
FIGURE 8.22 (a) Tool-life curves for a variety of cutting-tool materials. The negative inverse of the
slope of these curves is the exponent n in tool-life equations. (b) Relationship between measured
temperature during cutting and tool life (ﬂank wear). Note that high cutting temperatures severely
reduce tool life. See also Eq. (8.30). Source: After H.Takeyama andY. Murata.
300
50 300
m/min
3000
100
300
100
10
20
Toollife(min)
5
1
10,00050001000
n
High-speedsteel
Castalloy
CarbideCeramic
Feed constant,
speed variable
Speed constant,
feed variable
800 1000 1200 1400
°C
400
200
100
60
40
20
10
6
4
2
1
0.6
0.2
Toollife(min)
1500 1800 2100 2400
Temperature (°F)
Work material: Heat-resistant alloy
Tool material: Tungsten carbide
Tool life criterion: 0.024 in. (0.6 mm) flank wear
(a) (b)

ISBN No. 0-13-227271-7
Tool Wear
FIGURE 8.23 Relationship between crater-
wear rate and average tool-chip interface
temperature in turning: (a) high-speed-steel
tool; (b) C1 carbide; (c) C5 carbide. Note
that crater wear increases rapidly within a
narrow range of temperature. Source: After
K.J.Trigger and B.T. Chao.
Average tool-chip interface
temperature (°F)
800 1200 1600 2000
0.15
0.3020
500 700 900 1100
10
0 0
°C
mm3/min
Craterwearrate
(in3/minx10-6)
a b c
Allowable Wear Land (mm)
Operation High-Speed Steels Carbides
Turning 1.5 0.4
Face milling 1.5 0.4
End milling 0.3 0.3
Drilling 0.4 0.4
Reaming 0.15 0.15
TABLE 8.5 Allowable average wear lands for
cutting tools in various operations.
Rake face
Crater wear
Chip Flank face
FIGURE 8.23 Interface of chip (left) and rake
face of cutting tool (right) and crater wear in
cutting AISI 1004 steel at 3 m/s (585 ft/min).
Discoloration of the tool indicates the
presence of high temperature (loss of
temper). Note how the crater-wear pattern
coincides with the discoloration pattern.
Compare this pattern with the temperature
distribution shown in Fig. 8.16. Source:
Courtesy of P.K.Wright.

ISBN No. 0-13-227271-7
Acoustic Emission and Wear
FIGURE 8.25 Relationship between mean ﬂank wear, maximum crater wear, and acoustic emission (noise generated
during cutting) as a function of machining time.This technique has been developed as a means for continuously and
indirectly monitoring wear rate in various cutting processes without interrupting the operation. Source: After M.S.
Lan and D.A. Dornfeld.
Crater wear
Flank wear
0.005
0.004
0.003
0.002
0.001
0
in. mm
0.15
0.1
0.05
0
Maximumcraterdepth
Meanflankwear
1.5
1.0
0.5
0
mm in.
MeanRMS(mV)
0.050
0.040
0.030
0.020
0.010
1500
1000
500
0
0 10 20 30 40 50 60
Elapsed machining time (min)

ISBN No. 0-13-227271-7
Surface Finish
FIGURE 8.26 Range of surface roughnesses
obtained in various machining processes. Note the
wide range within each group, especially in turning
and boring. (See also Fig. 9.27).
Flame cutting
Snagging (coarse grinding)
Sawing
Planing, shaping
Drilling
Chemical machining
Electrical-discharge machining
Milling
Broaching
Reaming
Electron-beam machining
Laser machining
Electrochemical machining
Turning, boring
Barrel finishing
Electrochemical grinding
Roller burnishing
Grinding
Honing
Electropolishing
Polishing
Lapping
Superfinishing
Process 2000 1000 500 250 125 63 32 16 8 4 2 1 0.5
50 25 12.5 6.3 3.2 1.6 0.8 0.40 0.20 0.10 0.05 0.025 0.012
Roughness (Ra)
µin.
µm
Average application
Less frequent application
Sand casting
Die casting
Hot rolling
Forging
Permanent mold casting
Investment casting
Extruding
Cold rolling, drawing
Rough cutting
Casting
Forming
Machining
Advanced machining
Finishing processes

ISBN No. 0-13-227271-7
Surfaces in Machining
FIGURE 8.27 Surfaces produced on steel in
machining, as observed with a scanning electron
microscope: (a) turned surface, and (b) surface
produced by shaping. Source: J.T. Black and S.
Ramalingam.
(a) (b)
FIGURE 8.28 Schematic illustration of a dull tool in orthogonal
cutting (exaggerated). Note that at small depths of cut, the rake
angle can effectively become negative. In such cases, the tool may
simply ride over the workpiece surface, burnishing it, instead of
cutting.
Increasingdepth
ofcut
Workpiece Machined
surface
Tool

ISBN No. 0-13-227271-7
Inclusions in Free-Machining Steels
FIGURE 8.29 Photomicrographs showing various types of inclusions in low-carbon, resulfurized free-
machining steels. (a) Manganese-sulfide inclusions in AISI 1215 steel. (b) Manganese-sulfide inclusions and
glassy manganese-silicate-type oxide (dark) in AISI 1215 steel. (c) Manganese sulfide with lead particles as
tails in AISI 12L14 steel. Source: Courtesy of Ispat Inland Inc.
(a) (b) (c)

ISBN No. 0-13-227271-7
Hardness of Cutting Tools
FIGURE 8.30 Hardness of various cutting-tool
materials as a function of temperature (hot hardness).
The wide range in each group of tool materials results
from the variety of compositions and treatments
available for that group.
0
55
60
65
70
75
80
85
90
95
100 300 500 700
200 400 600 800 1000 1200 1400
20
25
30
35
40
45
50
55
60
65
70
Hardness(HRA)
HRC
Temperature (°F)
°C
Ceramics
Carbides
High-speedsteels
Cast alloys
Car
bon
toolsteels

ISBN No. 0-13-227271-7
Tool Materials
Carbides
Cubic Single
High-Speed Cast Boron Crystal
Property Steel Alloys WC TiC Ceramics Nitride Diamond∗
Hardness 83-86 HRA 82-84 HRA 90-95 HRA 91-93 HRA 91-95 HRA 4000-5000 HK 7000-8000 HK
Compressive strength
MPa 4100-4500 1500-2300 4100-5850 3100-3850 2750-4500 6900 6900
psi ×103
600-650 220-335 600-850 450-560 400-650 1000 1000
Transverse rupture
strength
MPa 2400-4800 1380-2050 1050-2600 1380-1900 345-950 700 1350
psi ×103
350-700 200-300 150-375 200-275 50-135 105-200
Impact strength
J 1.35-8 0.34-1.25 0.34-1.35 0.79-1.24 < 0.1 < 0.5 < 0.2
in.-lb 12-70 3-11 3-12 7-11 < 1 < 5 < 2
Modulus of elasticity
GPa 200 — 520-690 310-450 310-410 850 820-1050
psi ×106
30 — 75-100 45-65 45-60 125 120-150
Density
kg/m3
8600 8000-8700 10,000-15,000 5500-5800 4000-4500 3500 3500
lb/in3
0.31 0.29-0.31 0.36-0.54 0.2-0.22 0.14-0.16 0.13 0.13
Volume of hard
phase (%) 7-15 10-20 70-90 — 100 95 95
Melting or decom-
position temperature
◦
C 1300 — 1400 1400 2000 1300 700
◦
F 2370 — 2550 2550 3600 2400 1300
Thermal conductivity,
W/mK 30-50 — 42-125 17 29 13 500-2000
Coeﬃcient of thermal
expansion, ×10−6
/◦
C 12 — 4-6.5 7.5-9 6-8.5 4.8 1.5-4.8
∗
The values for polycrystalline diamond are generally lower, except impact strength, which is higher.
TABLE 8.6 Typical range of properties of various tool materials.

ISBN No. 0-13-227271-7
Properties of Tungsten-Carbide Tools
FIGURE 8.31 Effect of cobalt content in tungsten-carbide tools on mechanical properties. Note
that hardness is directly related to compressive strength (see Section 2.6.8) and hence, inversely
to wear [see Eq. (4.6)].
Wear(mg),compressiveandtransverse-
rupturestrength(kg/mm2)
Cobalt content (% by weight)
Vickershardness(HV)
600
500
400
300
200
100
0
0 5 10 15 20 25 30
1750
1500
1250
1000
750
500
HRA 92.4
90.5
88.5
85.7
Compressive strength
Hardness
Wear
Transverse-rupture strength

ISBN No. 0-13-227271-7
Inserts
FIGURE 8.32 Methods of mounting inserts on toolholders: (a) clamping, and (b) wing lockpins. (c)
Examples of inserts mounted using threadless lockpins, which are secured with side screws. Source:
Courtesy ofValenite.
(c)(b)
Shank
Seat
Lockpin
Insert
(a)
Insert
Clamp
Clamp
screw
Seat
or shim
Toolholder

ISBN No. 0-13-227271-7
Insert Strength
FIGURE 8.33 Relative edge strength and tendency for
chipping and breaking of inserts with various shapes.
Strength refers to that of the cutting edge shown by the
included angles. Source: Courtesy of Kennametal, Inc.
90°100° 80° 60° 55° 35°
Increasing strength
Increased chipping and breaking
FIGURE 8.34 Edge preparations for inserts to improve edge
strength. Source: Courtesy of Kennametal, Inc.
Negative
withland
andhone
Negative
withland
Negative
honed
Negative
sharp
Positive
withhone
Positive
sharp
Increasing edge strength

ISBN No. 0-13-227271-7
Historical Tool Improvement
FIGURE 8.35 Relative time required to machine with various cutting-tool materials, with
indication of the year the tool materials were introduced. Note that, within one century,
machining time has been reduced by two orders of magnitude. Source:After Sandvik Coromant.
Carbon steel
High-speed steel
Cast cobalt-based alloys
Cemented carbides
Improved carbide grades
First coated grades
First double-coated grades
First triple-coated grades
1900 !10 !20 !30 !40 !50 !60 !70 !80 !90
100
26
15
6
3
1.5
1
0.7
Machiningtime(min)
Year
!00
0.5 Functionally graded triple-coated

ISBN No. 0-13-227271-7
Coated Tools
FIGURE 8.36 Wear patterns on high-speed-steel
uncoated and titanium-nitride-coated cutting
tools. Note that ﬂank wear is lower for the
coated tool.
TiN coated
Uncoated
Flank wear
Rake
face
Tool
FIGURE 8.37 Multiphase coatings on a tungsten-carbide
substrate. Three alternating layers of aluminum oxide are
separated by very thin layers of titanium nitride. Inserts with as
many as 13 layers of coatings have been made. Coating
thicknesses are typically in the range of 2 to 10 µm. Source:
Courtesy of Kennametal, Inc.
TiN
TiN
TiN
TiC + TiN
TiC + TiN
Carbide substrate
Al2O3
Al2O3
Al2O3

ISBN No. 0-13-227271-7
Properties of Cutting Tool Materials
FIGURE 8.38 Ranges of properties for various groups of cutting-tool
materials. (See also Tables 8.1 through 8.5.)
Hothardnessandwearresistance
Strength and toughness
Diamond, cubic boron nitride
Aluminum oxide (HIP)
Aluminum oxide + 30% titanium carbide
Silicon nitride
Cermets
Coated carbides
Carbides
HSS
FIGURE 8.39 Construction of polycrystalline cubic-
boron-nitride or diamond layer on a tungsten-carbide
insert.
Braze
Polycrystalline
cubic boron nitride
or diamond layer
Carbide substrate
Tungsten-carbide
insert

ISBN No. 0-13-227271-7
Characteristics of Machining
Commercial tolerances
Process Characteristics (±mm)
Turning Turning and facing operations are performed on all types of
materials; requires skilled labor; low production rate, but
medium to high rates can be achieved with turret lathes and
automatic machines, requiring less skilled labor.
Fine: 0.05-0.13
Rough: 0.13
Skiving: 0.025-0.05
Boring Internal surfaces or profiles, with characteristics similar to
those produced by turning; stiffness of boring bar is impor-
tant to avoid chatter.
0.025
Drilling Round holes of various sizes and depths; requires boring and
reaming for improved accuracy; high production rate, labor
skill required depends on hole location and accuracy specified.
0.075
Milling Variety of shapes involving contours, flat surfaces, and slots;
wide variety of tooling; versatile; low to medium production
rate; requires skilled labor.
0.13-0.25
Planing Flat surfaces and straight contour profiles on large surfaces;
suitable for low-quantity production; labor skill required de-
pends on part shape.
0.08-0.13
Shaping Flat surfaces and straight contour profiles on relatively small
workpieces; suitable for low-quantity production; labor skill
required depends on part shape.
0.05-0.13
Broaching External and internal flat surfaces, slots, and contours with
good surface finish; costly tooling; high production rate; labor
skill required depends on part shape.
0.025-0.15
Sawing Straight and contour cuts on flats or structural shapes; not
suitable for hard materials unless the saw has carbide teeth
or is coated with diamond; low production rate; requires only
low skilled labor.
0.8
TABLE 8.7 General characteristics of machining processes.

ISBN No. 0-13-227271-7
Lathe Operations
FIGURE 8.40 Variety of machining operations
that can be performed on a lathe.
Depth
of cut
ToolFeed, f
(a) Straight turning
(g) Cutting with
a form tool
(e) Facing
(b) Taper turning (c) Profiling
(k) Threading
(d) Turning and
external grooving
(f) Face grooving
(h) Boring and
internal grooving
(i) Drilling
(j) Cutting off (l) Knurling
Workpiece

ISBN No. 0-13-227271-7
Tool Angles
FIGURE 8.41 Designations and
symbols for a right-hand cutting tool.
The designation “right hand” means
that the tool travels from right to left,
as shown in Fig. 8.19.
High-speed steel Carbide inserts
Material Back Side End Side Side and end Back Side End Side Side and end
rake rake relief relief cutting edge rake rake relief relief cutting edge
Aluminum and
magnesium alloys 20 15 12 10 5 0 5 5 5 15
Copper alloys 5 10 8 8 5 0 5 5 5 15
Steels 10 12 5 5 15 -5 -5 5 5 15
Stainless steels 5 8-10 5 5 15 -5-0 -5-5 5 5 15
High-temperature 0 10 5 5 15 5 0 5 5 45
alloys
Refractory alloys 0 20 5 5 5 0 0 5 5 15
Titanium alloys 0 5 5 5 15 -5 -5 5 5 5
Cast irons 5 10 5 5 15 -5 -5 5 5 15
Thermoplastics 0 0 20-30 15-20 10 0 0 20-30 15-20 10
Thermosets 0 0 20-30 15-20 10 0 15 5 5 15
(a) End view (b) Side view
Shank
Flank face
Back rake
angle (BRA)
End relief
angle (ERA)
Wedge
angle
Side rake
angle (RA)
Side relief
angle (SRA)
(c) Top view
Rake face
End cutting-edge
angle (ECEA)
Side cutting-edge
angle (SCEA)
Nose
angle
Nose
radius
TA B L E 8 . 8 G e n e r a l
recommendations for tool angles
in turning.

ISBN No. 0-13-227271-7
Turning Operations
FIGURE 8.42 (a) Schematic illustration of a turning operation, showing depth of cut, d, and feed, f. Cutting speed
is the surface speed of the workpiece at the tool tip. (b) Forces acting on a cutting tool in turning. Fc is the
cutting force; Ft is the thrust or feed force (in the direction of feed); and Fr is the radial force that tends to push
the tool away from the workpiece being machined. Compare this ﬁgure with Fig. 8.11 for a two-dimensional
cutting operation.
(a) (b)
d
DoDf
Workpiece
N
Chuck
Tool
Feed, f
Tool
Feed, f
N
Fc
Ft Fr

ISBN No. 0-13-227271-7
Cutting Speeds for Turning
FIGURE 8.43 The range of applicable cutting
speeds and feeds for a variety of cutting-tool
materials.
Cubic boron nitride,
diamond, and
ceramics
Cermets
Coated
carbides
Uncoated
carbides
3000
2000
1000
500
300
200
Cuttingspeed(ft/min)
0.004 0.008 0.012 0.020 0.030
Feed (in./rev)
0.10 0.20 0.30 0.50 0.75
mm/rev
900
600
300
150
100
50
m/min
Cutting Speed
Workpiece Material m/min ft/min
Aluminum alloys 200-1000 650-3300
Cast iron, gray 60-900 200-3000
Copper alloys 50-700 160-2300
High-temperature alloys 20-400 65-1300
Steels 50-500 160-1600
Stainless steels 50-300 160-1000
Thermoplastics and thermosets 90-240 300-800
Titanium alloys 10-100 30-330
Tungsten alloys 60-150 200-500
Note: (a) The speeds given in this table are for carbides and ce-
ramic cutting tools. Speeds for high-speed-steel tools are lower
than indicated. The higher ranges are for coated carbides and cer-
mets. Speeds for diamond tools are signiﬁcantly higher than any
of the values indicated in the table.
(b) Depths of cut, d, are generally in the range of 0.5-12 mm (0.02-
0.5 in.).
(c) Feeds, f, are generally in the range of 0.15-1 mm/rev (0.006-
0.040 in./rev).
TABLE 8.9 Approximate Ranges of Recommended
Cutting Speeds for Turning Operations

ISBN No. 0-13-227271-7
Lathe
FIGURE 8.44 General view of a typical lathe, showing various major components. Source: Courtesy of
Heidenreich & Harbeck.
Spindle speed
selector
Headstock assembly
Spindle (with chuck)
Tool post
Compound
rest
Cross slide
Carriage
Ways
Dead center
Tailstock quill
Tailstock
assembly
Handwheel
Bed
Feed selector
Clutch
Chip pan
Apron
Split nut
Clutch
Longitudinal &
transverse feed
control
Feed rod
Lead screw

ISBN No. 0-13-227271-7
CNC Lathe
FIGURE 8.45 (a) A computer-numerical-control lathe, with two turrets; these machines have higher power and
spindle speed than other lathes in order to take advantage of advanced cutting tools with enhanced properties;
(b) a typical turret equipped with ten cutting tools, some of which are powered.
Drill
Multitooth
cutter
Tool for
turning
or boring
Reamer
Individual
motors
Drill
Round turret for
OD operationsCNC unit Chuck
End turret for ID operations Tailstock
(a) (b)

ISBN No. 0-13-227271-7
Typical CNC Parts
FIGURE 8.46 Typical parts made on computer-numerical-control machine tools.
(a) Housing base
Material: Titanium alloy
Number of tools: 7
Total machining time
(two operations):
5.25 minutes
Material: 52100 alloy steel
Number of tools: 4
(two operations):
6.32 minutes
(c) Tube reducer
Material: 1020 Carbon Steel
Number of tools: 8
(two operations):
5.41 minutes
(b) Inner bearing race
67.4 mm
(2.654")
87.9 mm
(3.462")
98.4 mm
(3.876")
85.7 mm (3.375")
32 threads per in.
235.6 mm
(9.275")
78.5 mm
(3.092")
50.8 mm
(2")
23.8 mm
(0.938")
53.2 mm
(2.094")

ISBN No. 0-13-227271-7
Typical Production Rates
Operation Rate
Turning
Engine lathe Very low to low
Tracer lathe Low to medium
Turret lathe Low to medium
Computer-control lathe Low to medium
Single-spindle chuckers Medium to high
Multiple-spindle chuckers High to very high
Boring Very low
Drilling Low to medium
Milling Low to medium
Planing Very low
Gear cutting Low to medium
Broaching Medium to high
Sawing Very low to low
Note: Production rates indicated are relative: Very low is about
one or more parts per hour; medium is approximately 100 parts
per hour; very high is 1000 or more parts per hour.
TABLE 8.10 Typical production rates for various cutting operations.

ISBN No. 0-13-227271-7
Boring Mill
FIGURE 8.47 Schematic illustration of the components of a vertical boring mill.
Cross-rail
Tool head
Workpiece
Work table
Bed
Column

ISBN No. 0-13-227271-7
Drills
FIGURE 8.48 Two common types of
drills: (a) Chisel-point drill.The function
of the pair of margins is to provide a
bearing surface for the drill against
walls of the hole as it penetrates into
the workpiece. Drills with four margins
(double-margin) are available for
improved drill guidance and accuracy.
Drills with chip-breaker features are
also available. (b) Crankshaft drills.
These drills have good centering ability,
and because chips tend to break up
easily, they are suitable for producing
deep holes.
(a) Chisel-point drill
Tang drive
Shank
diameter
Straight
shank
Neck
Overall length
Flute length
Body
Point angle
Lip-relief
angle
Chisel-edge
angle
Chisel edge
Drill
diameter
Body diameter
clearance
Clearance
diameter
(b) Crankshaft-point drill
Lip
Margin
Land
Flutes Helix angle
Shank length
Web
Tang Taper shank
Drilling
Coredrilling
Stepdrilling
Counterboring
Countersinking
Reaming
Centerdrilling
Gundrilling
High-pressure
coolant
FIGURE 8.49 Various types of drills and drilling operations.

ISBN No. 0-13-227271-7
Speeds and Feeds in Drilling
Surface Feed, mm/rev (in./rev) Spindle speed (rpm)
Speed Drill Diameter Drill Diameter
Workpiece 1.5 mm 12.5 mm 1.5 mm 12.5 mm
Material m/min ft/min (0.060 in.) (0.5 in.) (0.060 in.) (0.5 in.)
Aluminum alloys 30-120 100-400 0.025 (0.001) 0.30 (0.012) 6400-25,000 800-3000
Magnesium alloys 45-120 150-400 0.025 (0.001) 0.30 (0.012) 9600-25,000 1100-3000
Copper alloys 15-60 50-200 0.025 (0.001) 0.25 (0.010) 3200-12,000 400-1500
Steels 20-30 60-100 0.025 (0.001) 0.30 (0.012) 4300-6400 500-800
Stainless steels 10-20 40-60 0.025 (0.001) 0.18 (0.007) 2100-4300 250-500
Titanium alloys 6-20 20-60 0.010 (0.0004) 0.15 (0.006) 1300-4300 150-500
Cast irons 20-60 60-200 0.025 (0.001) 0.30 (0.012) 4300-12,000 500-1500
Thermoplastics 30-60 100-200 0.025 (0.001) 0.13 (0.005) 6400-12,000 800-1500
Thermosets 20-60 60-200 0.025 (0.001) 0.10 (0.004) 4300-12,000 500-1500
Note: As hole depth increases, speeds and feeds should be reduced. Selection of speeds and
feeds also depends on the speciﬁc surface ﬁnish required.
TABLE 8.11 General recommendations for speeds and feeds in drilling.

ISBN No. 0-13-227271-7
Reamers and Taps
FIGURE 8.50 Terminology for a helical reamer.
Chamfer angle
Chamfer length
Chamfer relief
Helix angle, -
Primary
relief angle
Margin
width
Land width
Radial rake
FIGURE 8.51 (a) Terminology for a tap;
(b) illustration of tapping of steel nuts in
high production.
(b)
Rake angle
Hook angle
(a)
Tap
Nut
Land
Chamfer
relief
Flute
Cutting edge
Heel
Chamfer
angle

ISBN No. 0-13-227271-7
Typical Machined Parts
FIGURE 8.52 Typical parts and shapes produced by the machining processes
described in Section 8.10.
(a) (b) (c)
(d) (e) (f)
Drilled and
tapped holes
Stepped
cavity

ISBN No. 0-13-227271-7
Conventional and Climb Milling
(a) (b) (c)
Workpiece
Conventional
milling
Climb
milling
d
N
D
f
tc
d
v
Cutter
D
v
llc
Workpiece
Cutter
FIGURE 8.53 (a) Illustration showing the difference between conventional milling and climb
milling. (b) Slab-milling operation, showing depth of cut, d; feed per tooth, f; chip depth of
cut, tc and workpiece speed, v. (c) Schematic illustration of cutter travel distance, lc, to reach
full depth of cut.

ISBN No. 0-13-227271-7
Face Milling
f
w
v
lc
lc
l
Workpiece
D
Cutter
(b)
f
v
(c)(a)
Insert
(d)
l
d
w
v
Machined surface
Workpiece
Cutter
FIGURE 8.54 Face-milling operation
showing (a) action of an insert in face
milling; (b) climb milling; (c) conventional
milling; (d) dimensions in face milling.
Peripheral relief
(radial relief)
Radial
rake, 2
Axial rake, 1
End cutting-edge angle
Corner
angle
End relief
(axial relief)
FIGURE 8.55 Terminology for a face-
milling cutter.

ISBN No. 0-13-227271-7
Cutting Mechanics
Insert
Undeformed chip thickness
Depth of cut, d
Lead
angle
f
Feed per tooth, f
(a) (b)
FIGURE 8.56 The effect of lead angle on the
undeformed chip thickness in face milling. Note that as
the lead angle increases, the undeformed chip
thickness (and hence the thickness of the chip)
decreases, but the length of contact (and hence the
width of the chip) increases. Note that the insert must
be sufficiently large to accommodate the increase in
contact length.
(b)
Exit
Entry
Re-entry
Exit
(a)
Cutter
Workpiece
(c)
Cutter
Desirable
Milled
surface
+ -
Undesirable
FIGURE 8.57 (a) Relative
position of the cutter and the
insert as it first engages the
workpiece in face milling, (b)
insert positions at entry and exit
near the end of cut, and (c)
examples of exit angles of the
insert, showing desirable (positive
or negative angle) and undesirable
(zero angle) positions. In all
figures, the cutter spindle is
perpendicular to the page.

ISBN No. 0-13-227271-7
Milling Operations
(a) Straddle milling (b) Form milling
Arbor
(c) Slotting (d) Slitting
FIGURE 8.58 Cutters for (a) straddle
milling; (b) form milling; (c) slotting; and (d)
slitting operations.
Cutting Speed
Workpiece Material m/min ft/min
Aluminum alloys 300-3000 1000-10,000
Cast iron, gray 90-1300 300-4200
Copper alloys 90-1000 300-3300
High-temperature alloys 30-550 100-1800
Steels 60-450 200-1500
Stainless steels 90-500 300-1600
Thermoplastics and thermosets 90-1400 300-4500
Titanium alloys 40-150 130-500
Note: (a) These speeds are for carbides, ceramic, cermets, and diamond cutting
tools. Speeds for high-speed-steel tools are lower than those indicated in this table.
(b) Depths of cut, d, are generally in the range of 1-8 mm (0.04-0.3 in.).
(c) Feeds per tooth, f, are generally in the range of 0.08-0.46 mm/rev (0.003-0.018
in./rev).
TABLE 8.12 Approximate range of recommended cutting
speeds for milling operations.

ISBN No. 0-13-227271-7
Milling Machines
(a) (b)
Work
tableHead
Column
Base
Workpiece
Saddle
Knee
Overarm
Arbor
Column
Workpiece
Work table
Saddle
Knee
Base
T-slots T-slots
FIGURE 8.59 (a) Schematic illustration of a horizontal-spindle column-and-knee-type milling
machine. (b) Schematic illustration of a vertical-spindle column-and-knee-type milling machine.
Source: After G. Boothroyd.

ISBN No. 0-13-227271-7
Broaching
(a)
(b) (c)
FIGURE 8.60 (a) Typical parts ﬁnished by internal broaching. (b) Parts ﬁnished by surface
broaching. The heavy lines indicate broached surfaces; (c) a vertical broaching machine. Source:
(a) and (b) Courtesy of General Broach and Engineering Company, (c) Courtesy of Ty Miles, Inc.

ISBN No. 0-13-227271-7
Broaches
(b)
Root radius
Pitch
LandRake or
hook angle
Tooth
depth
Backoff or
clearance angle
(a)
Cut per
tooth
Chip gullet
Workpiece
FIGURE 8.61 (a) Cutting action of a
broach, showing various features. (b)
Terminology for a broach.
Pull end
Root diameter
Follower
diameter
Overall length
Shank length
Front
pilot
Roughening
teeth
Cutting teeth
Semifinishing teeth
Rear pilot
Finishing
teeth
FIGURE 8.62 Terminology for a pull-type
internal broach, typically used for enlarging
long holes.

ISBN No. 0-13-227271-7
Saws and Saw Teeth
(a) (b)
Straight tooth
Raker tooth
Wave tooth
Tooth set
Width
Back edge
Tooth
spacing
Tooth face
Tooth back
(flank)
Tooth back
clearance angle
Tooth rake
angle (positive)
Gullet
depth
FIGURE 8.63 (a) Terminology for
saw teeth. (b) Types of saw teeth,
staggered to provide clearance for
the saw blade to prevent binding
during sawing.
M2 HSS 64-66 HRC
Electron-beam weld
(a) (b)
Carbide
insert
Flexible alloy-steel
backing
FIGURE 8.64 (a) High-speed-steel teeth
welded on a steel blade. (b) Carbide inserts
brazed to blade teeth.

ISBN No. 0-13-227271-7
Gear
Manufacture
(b)(a)
(c) (d)
Top view
Gear
blank
Hob
Gear blank
Hob
Rack-shaped cutter
Gear blank
Gear cutter Base circle
Gear blank
Pitch circle
Pitch circle
Base circle
Gear
teeth
Pinion-shaped
cutter
Gear blank
Spacer
Cutter spindle
FIGURE 8.65 (a) Schematic illustration
of gear generating with a pinion-shaped
gear cutter. (b) Schematic illustration of
gear generating in a gear shaper, using a
pinion-shaped cutter; note that the
cutter reciprocates vertically. (c) Gear
generating with a rack-shaped cutter. (d)
Three views of gear cutting with a hob.
Source: After E.P. DeGarmo.

ISBN No. 0-13-227271-7
Machining Centers
Tools (cutters)
Index table
Tool storage Tool-interchange arm
Traveling column
Spindle
Pallets
Bed
Spindle carrier
Computer
numerical-control panel
FIGURE 8.67 Schematic illustration of a
computer numerical-controlled turning center.
Note that the machine has two spindle heads
and three turret heads, making the machine
tool very ﬂexible in its capabilities. Source:
Courtesy of Hitachi Seiki Co., Ltd.
1st Spindle head
2nd Turret head
1st Turret head
2nd Spindle head
3rd Turret head
FIGURE 8.66 A horizontal-spindle machining center,
equipped with an automatic tool changer.Tool magazines
in such machines can store as many as 200 cutting tools,
each with its own holder. Source: Courtesy of Cincinnati
Machine.

ISBN No. 0-13-227271-7
Reconﬁgurable Machines
Magazine unit
Arm unit
Rotational motion
Arm unitBase unitBed unit
Linear motion
Linear motion
Functional unit
Rotational
motion
FIGURE 8.68 Schematic illustration of a reconﬁgurable modular machining center, capable of
accommodating workpieces of different shapes and sizes, and requiring different machining
operations on their various surfaces. Source: AfterY. Koren.

ISBN No. 0-13-227271-7
Reconﬁgurable Machining Center
(a) (b) (c)
FIGURE 8.69 Schematic illustration of assembly of different components of a
reconﬁgurable machining center. Source: AfterY. Koren.

ISBN No. 0-13-227271-7
Machining of Bearing Races
1. Finish turning of
outside diameter
2. Boring and grooving
on outside diameter
3. Internal grooving
with a radius-form tool
4. Finish boring of internal
groove and rough boring
of internal diameter
5. Internal grooving
with form tool
and chamfering
6. Cutting off finished
part; inclined bar
picks up bearing race
Tube
Bearing
race
Form
tool
Form tool
FIGURE 8.70 Sequences involved in machining outer bearing races on a turning center.

ISBN No. 0-13-227271-7
Hexapod
(a) (b)
Spindle
Hexapod
legs
Cutting tool
Workpiece
FIGURE 8.71 (a) A hexapod machine tool, showing its major components. (b) Closeup view of the cutting
tool and its head in a hexapod machining center. Source: National Institute of Standards and Technology.

ISBN No. 0-13-227271-7
Chatter &Vibration
FIGURE 8.72 Chatter marks (right
of center of photograph) on the
surface of a turned part. Source:
Courtesy of General Electric
Company.
1.2
0.8
0.4
0.0
-0.4
-0.8
-1.2
-1.6
-2.0
0 1000 2000 3000 4000
10-5 s
10-1V
Cast iron
(a)
1.2
0.8
0.4
0.0
20.4
20.8
21.2
21.6
22.0
0 1000 2000 3000 4000
10-5 s
10-1V
Epoxy/graphite
(b)
FIGURE 8.73 Relative damping capacity of (a) gray cast iron and (b) epoxy-granite
composite material. The vertical scale is the amplitude of vibration and the
horizontal scale is time.
Increasingdamping
Bed
only
Bed +
carriage
Bed +
headstock
Bed +
carriage +
headstock
Complete
machine
FIGURE 8.74 Damping of vibrations as a
function of the number of components on a
lathe. Joints dissipate energy; thus, the greater the
number of joints, the higher the damping. Source:
After J. Peters.

ISBN No. 0-13-227271-7
Machining EconomicsTotal cost
Machining cost
Nonproductive cost
Tool-change cost
Tool cost
(a)
Costperpiece
Cutting speed
Machining time
Total time
Nonproductive time
Tool-changing time
(b)
High-efficiency machining range
Cutting speed
Timeperpiece
FIGURE 8.75 Qualitative plots showing (a) cost per piece,
and (b) time per piece in machining. Note that there is an
optimum cutting speed for both cost and time, respectively.
The range between the two optimum speeds is known as the
high-efﬁciency machining range.

ISBN No. 0-13-227271-7
Case Study: Ping Golf Putters
FIGURE 8.76 (a) The Ping Anser® golf putter; (b) CAD model of rough machining of the putter outer surface; (c) rough machining
on a vertical machining center; (d) machining of the lettering in a vertical machining center; the operation was paused to take the
photo, as normally the cutting zone is ﬂooded with a coolant; Source: Courtesy of Ping Golf, Inc.

Ch08

Recommended

Recommended

More Related Content

What's hot

What's hot (20)

Viewers also liked

Viewers also liked (14)

Similar to Ch08

Similar to Ch08 (20)

Recently uploaded

Recently uploaded (20)

Ch08