PowerPoint to accompany
Technology of Machine Tools
6th Edition
Krar • Gill • Smid
Hand Tools And
Bench Work
Section 7
Copyright © The McGraw-Hill Companies, Inc.
Permission required for reproduction or display.
22-2
Machine Tool Trade
• Two categories
– Hand tool
– Machine tool operations
• Importance of hand tools should not be
overlooked
• Bench work includes operations of laying
out, fitting, and assembling
PowerPoint to accompany
Technology of Machine Tools
6th Edition
Krar • Gill • Smid
Holding, Striking, and
Assembling Tools
Unit 22
Copyright © The McGraw-Hill Companies, Inc.
Permission required for reproduction or display.
22-4
Objectives
• Select various tools used for holding,
assembling, or dismantling workpieces
• Properly use these tools for holding,
assembling, and dismantling workpieces
22-5
Two Classes of Hand Tools
• Noncutting
– Include vises, hammers, screwdrivers,
wrenches and pliers
– Used basically for holding, assembling or
dismantling parts
• Cutting
22-6
Bench Vise
• Jaw
Usedcaps
to hold
madesmall
of brass,
work securely
for to
aluminum,
or copper
protect
work surface
sawing,the
chipping,
from
marred or
filing,being
polishing,
damaged
drilling, reaming,
and tapping
• Size determined
by width of jaws
Copyright © The McGraw-Hill Companies, Inc.
Permission required for reproduction or display.
Solid or swivel base
22-7
Ball-Peen Hammer
• Most common
• Face: larger striking surface
• Peen: smaller, rounded end
– Used in riveting or peening operations
• Variety of sizes: head mass range 2 oz to 3 lb
– Smaller sizes used for layout work
– Larger sizes used for general work
22-8
Soft-Faced Hammers
• Heads made of plastic, rawhide, copper or lead
– Fastened to steel body and replaced when worn
– Used in assembling or dismantling parts so finished
surface of work not marred
• Lead hammers
– Used to seat workpiece properly on parallels
• Plastic hammer heads
– Filled with lead or steel shot
– Do not lose shape and last longer than lead hammers
• Grasp end of handle for better balance and greater
striking force
22-9
Safety Precautions When
Using a Hammer
1. Be sure handle is solid and not cracked
2. See head is tight on handle and secured
with proper wedge to keep handle
expanded in head
3. Never use with greasy handle or when
your hands are greasy
4. Never strike two hammer faces together
22-10
Screwdrivers
• Two most common types
– Standard or flat blade
• Blades for smaller make of round stock
• Blades for larger often square for leverage
– Phillips
• Different sizes and styles
– Standard shank
– Stubby shank
– Offset
22-11
Phillips Screwdrivers
• + shaped tip for use with Phillips-type
recessed screw heads
• Manufactured in four sizes: #1, #2, #3, #4
– To suit various-sized recesses in heads of
fasteners
• Use proper size screwdriver
• Hold firmly in recess and square with screw
22-12
Care of a Screwdriver
1. Choose correct size of screwdriver for job
•
Too small, both screw slot and tip of
screwdriver may become damaged
2. Do not use screwdriver as pry, chisel, or
wedge
3. When tip of standard screwdriver becomes
worn or broken, redress to shape
22-13
Regrinding a Standard
Screwdriver Blade
• Make sides of blade slightly concave by holding
side of blade tangential to periphery of grinding
wheel
• Grind equal amount off each side of blade
• Shape will enable blade to maintain better grip in
slot
• Retain original taper, width, and thickness of tip
and grind end square with centerline
• Remove minimum amount of metal
• Quench tip frequently in cold water
22-14
Wrenches
•
Many types used in machine shop work
–
Each suited for specific purpose
•
•
Name derived from use, shape, or construction
Most available in both inch and metric
measuring systems
22-15
Open-End Wrenches
1. Single-ended or double-ended
• Openings usually offset at 15º angle
–
–
Permits turning nut or bolt head in limited
spaces by "flopping" wrench
Double-ended have different-size opening at
each end
22-16
Box-End 12-Point Wrenches
• Completely surround nut and useful in close
quarters where only small rotation of nut can
be obtained at one time
• Box end has 12 precisely cut notches around
inside face
– Notches fit closely over points on outside of nut
– Cannot slip when proper size used
• Have different size at each end
22-17
Socket Wrenches
• Similar to box wrenches
– Twelve points and surround nut
• Types of drives
– Ratchet
– Torque-wrench handles
• Used when nuts or bolts must be tightened to within
certain limits
22-18
Adjustable Wrenches
• May be adjusted to within certain range to
fit several sizes of nuts or bolt heads
• Useful for odd-size nuts or when proper size
not available
– Can slip when not properly adjusted to flats of
nut
22-19
Allen Setscrew Wrenches
• Commonly called hex keys
• Hexagonal and fit into recesses of socket
head setscrews
• Made of tool steel
• Available in sets to fit wide variety of screw
sizes
– Indicated size is distance across flats of wrench
• ½ outside diameter of Allen setscrew in which used
22-20
Pin Spanner Wrenches
• Specialized wrenches supplied by machine
tool manufacturer for use on specific
machines
• Supplied in various sizes
• Fixed-face spanners and adjustable-face
spanners positioned in two holes on face of
special nut or threaded fitting on machine
• Hook-pin spanner used on circumference of
round nut
– Pin of spanner fits into hole in periphery of nut
22-21
Hints on Using Wrenches
1. Always select wrench that fits nut or bolt
properly
2. Pull rather than push on wrench
3. Always be sure nut is fully seated in wrench jaw
4. Use wrench in same plane as nut or bolt head
5. When tightening or loosening nut, give it sharp
quick jerk (more effective than steady pull)
6. Put drop of oil on threads when assembling a
bolt and nut to ensure easier removal later
22-22
Pliers
• Useful for gripping and holding small parts
for certain machining operations or when
assembling parts
• Many types and sizes
• Names by shape, function or construction
22-23
Types of Pliers
• Combination or slip-joint pliers
– Adjustable to grip both large and small work
• Grip work when small holes must be drilled or for
bending or twisting light, thin materials
• Side-cutting pliers
– Used mainly for cutting, gripping, and bending
of small diameter (1/8 in. or less) rods or wires
22-24
Types of Pliers
• Needle-nose pliers
– Available in both straight- and bent-nose types
– Useful for holding very small parts, positioning
them in hard-to-get-at places and bending wire
• Diagonal cutters
– Used solely for cutting wire and small pieces
soft metal
22-25
Types of Pliers
• Vise-grip pliers
– Extremely high gripping power because
of adjustable lever action
• screw in handle allows adjustment to
various sizes
– Several different styles: standard jaws,
needle jaws and C-clamp jaws
22-26
Hints on Using Pliers
1. Never use plier instead of wrench
2. Never attempt to cut large-diameter or
heat-treated material with pliers
3. Always keep pliers clean and lubricated