Mechanical Engineer’s Pocket Book

Mechanical Engineer's Pocket BookBook Title : Mechanical Engineer’s Pocket Book
Author(s)  : Roger Timings
Publisher   : Elsevier
Edition      : Third edition
Pages       : 768
PDF Size  : 4.37 Mb

Book Description:
The Mechanical Engineer’s Pocket Book by Roger Timings is a comprehensive collection of data for mechanical engineers and B.Tech, M.Tech mechanical engineering students. Collecting the data and information that is required to hand when designing, making or repairing mechanical devices and systems, book has been revised to keep pace with changes in technology and standards. The Mechanical Engineers Pocket Book deals current engineering practice and is supported by easy understanding of the fundamental principles of mechanical engineering.
Key features include the latest engineering info, covers engineering design issues, enhanced coverage of roller chain drives, pneumatic and hydraulic systems; and expanded and more accessible detail on statics, dynamics and mathematics.

Table of Contents:
Chapter 1: Engineering Mathematics
1.1 The Greek alphabet
1.2 Mathematical symbols
1.3 Units: SI
1.3.1 Basic and supplementary units
1.3.2 Derived units
1.3.3 Units: not SI
1.3.4 Notes on writing symbols
1.3.5 Decimal multiples of units
1.4 Conversion factors for units
1.4.1 FPS to SI units
1.4.2 SI to FPS units
1.5 Preferred numbers
1.6 Mensuration
1.6.1 Plane figures
1.6.2 Solid objects
1.7 Powers, roots and reciprocals
1.8 Progressions
1.8.1 Arithmetic progressions
1.8.2 Geometric progressions
1.8.3 Harmonic progressions
1.9 Trigonometric formulae
1.9.1 Basic definitions
1.9.2 Identities
1.9.3 Compound and double angle formulae
1.9.4 ‘Product and sum’ formulae
1.9.5 Triangle formulae
1.10 Circles: some definitions and properties
1.10.1 Circles: areas and circumferences
1.11 Quadratic equations
1.12 Natural logarithms
1.13 Statistics: an introduction
1.13.1 Basic concepts
1.13.2 Probability
1.13.3 Binomial distribution
1.13.4 Poisson distribution
1.13.5 Normal distribution
1.14 Differential calculus (Derivatives)
1.15 Integral calculus (Standard forms)
1.15.1 Integration by parts
1.15.2 Definite integrals
1.16 Binomial theorem
1.17 Maclaurin’s theorem
1.18 Taylor’s theorem

Chapter 2: Engineering Statics
2.1 Engineering statics
2.2 Mass, force and weight
2.2.1 Mass
2.2.2 Force
2.2.3 Vectors
2.2.4 Weight
2.2.5 Mass per unit volume (density)
2.2.6 Weight per unit volume
2.2.7 Relative density
2.2.8 Pressure (fluids)
2.3 Vector diagrams of forces: graphical solution
2.3.1 Resultant forces
2.3.2 Parallelogram of forces
2.3.3 Equilibrant forces
2.3.4 Resolution of forces
2.3.5 Three forces in equilibrium (triangle of forces)
2.3.6 Polygon of forces: Bow’s notation
2.3.7 Non-concurrent coplanar forces (funicular link polygon)
2.4 Moments of forces, centre of gravity and centroids of areas
2.4.1 Moments of forces
2.4.2 Principle of moments (related terminology)
2.4.3 Principle of moments
2.4.4 Equilibrium
2.5 Orders of levers
2.5.1 First-order levers
2.5.2 Second-order levers
2.5.3 Third-order levers
2.6 Centre of gravity, centroids of areas and equilibrium
2.6.1 Centre of gravity (solid objects)
2.6.2 Centre of gravity of non-uniform and composite solids
2.6.3 Centre of gravity (lamina)
2.6.4 Centroids of areas
2.6.5 Equilibrium
2.7 Friction
2.7.1 Lubrication
2.7.2 Laws of friction
2.7.3 Coefficient of friction
2.7.4 Angle of friction
2.7.5 Friction on an inclined plane
2.7.6 Angle of repose
2.8 Stress and strain
2.8.1 Direct stress
2.8.2 Shear stress
2.8.3 Direct strain
2.8.4 Shear strain
2.8.5 Modulus of elasticity (Hooke’s law)
2.8.6 Modulus of rigidity
2.8.7 Torsional stress
2.8.8 Hoop stress in thin cylindrical shells
2.8.9 Longitudinal stress in thin cylindrical shells
2.9 Beams
2.9.1 Shearing force
2.9.2 Bending moment
2.9.3 Shearing force and bending moment diagrams
2.9.4 Beams (cantilever)
2.10 Stress, strain and deflections in beams
2.10.1 Bending stress and neutral axis
2.11 Frameworks
2.11.1 Method of sections
2.12 Hydrostatic pressure
2.12.1 Thrust on a submerged surface
2.12.2 Pascal’s law

Chapter 3: Engineering Dynamics
3.1 Engineering dynamics
3.2 Work
3.3 Energy
3.3.1 Conservation of energy
3.4 Power
3.5 Efficiency
3.6 Velocity and acceleration
3.6.1 Speed
3.6.2 Velocity
3.6.3 Acceleration
3.6.4 Equations relating to velocity and acceleration
3.6.5 Momentum
3.6.6 Newton’s laws of motion
3.6.7 Gravity
3.6.8 Conservation of momentum
3.6.9 Impact of a fluid jet on a fixed body
3.6.10 Inertia
3.6.11 Resisted motion
3.7 Angular motion
3.7.1 The radian
3.7.2 Angular displacement
3.7.3 Angular velocity
3.7.4 The relationship between angular and linear velocity
3.7.5 Angular acceleration
3.7.6 Torque
3.7.7 Work done by a torque
3.7.8 Centripetal acceleration and centripetal force
3.7.9 Centrifugal force
3.8 Balancing rotating masses
3.8.1 Balancing co-planar masses (static balance)
3.8.2 Balancing co-planar forces (dynamic balance)
3.9 Relative velocities
3.9.1 Relative velocities (unconnected bodies)
3.9.2 Relative velocities (connected bodies)
3.10 Kinematics
3.10.1 Ballistics
3.11 Kinetics
3.11.1 Universal gravitation
3.11.2 Linear translation
3.11.3 Translation in a curved path
3.11.4 Conic pendulum
3.11.5 Rotation of a body about a fixed axis
3.11.6 Radius of Gyration
3.11.7 Centre of percussion
3.11.8 Angular momentum
3.12 Simple harmonic motion
3.12.1 Simple pendulum
3.12.2 Natural vibration
3.13 Fluid dynamics
3.13.1 Rate of flow
3.13.2 Continuity of flow
3.13.3 Energy of a fluid in motion (Bernoulli’s equation)
3.13.4 Flow through orifices
3.13.5 Viscosity
3.13.6 Poiseulle’s formula
3.13.7 Stoke’s formula

Chapter 4: Fastenings
4.1 Screwed fastenings
4.1.1 Drawing proportions
4.1.2 Alternative screw heads
4.1.3 Alternative screw points
4.1.4 Hexagon socket cap head screw
4.1.5 Application of screwed fasteners
4.1.6 Acme thread form
4.1.7 Square thread form
4.1.8 Buttress thread form
4.1.9 V-thread form
4.1.10 Basic Whitworth (55°) thread form: parallel threads
4.1.11 ISO metric and ISO (60°) unified thread forms
4.1.12 Introduction to screwed fasteners
4.1.13 BS EN ISO 4014: 2001 Hexagon head bolts – product grades A and B
4.1.14 BS EN ISO 4016: 2001 Hexagon head bolts – product grades C
4.1.15 BS EN ISO 4017: 2001 Hexagon head screws – product grades A and B
4.1.16 BS EN ISO 4018: 2001 Hexagon head screws – product grade C
4.1.17 BS EN ISO 4032: 2001 Hexagon nuts style 1 – product grades A and B
4.1.18 BS EN ISO 4033: 2001 Hexagon nuts style 2 – product grades A and B
4.1.19 BS EN ISO 4034: 2001 Hexagon nuts style 1 – product grade C
4.1.20 BS EN ISO 4035: 2001 Hexagon thin nuts (chamfered) – product grades A and B
4.1.21 BS EN ISO 4036: 2001 Hexagon thin nuts (unchamfered) – product grade B
4.1.22 BS EN ISO 8765: 2001 Hexagon head bolts with metric fine pitch threads – product grades A and B
4.1.23 BS EN ISO 8676: 2001 Hexagon head screws with metric fine pitch threads – product grades A and B
4.1.24 BS EN ISO 8673: 2001 Hexagon nuts style 1 with metric fine pitch threads – product grades A and B
4.1.25 BS EN ISO 8674: 2001 Hexagon nuts style 2 with metric fine pitch threads – product grades A and B
4.1.26 BS EN ISO 8675: 2001 Hexagon thin nuts with metric fine pitch threads – product grades A and B
4.1.27 BS 7764: 1994 Hexagon slotted nuts and castle nuts
4.1.28 BS EN ISO: 898-1: 1999 Mechanical properties of fasteners: bolts, screws and studs
4.1.29 BS EN ISO 898-1: 1999 Marking
4.1.30 BS EN 20898-2: 1994 Mechanical properties of fasteners: nuts with specified proof load values – coarse thread
4.1.31 BS EN ISO 898-6: 1996 Mechanical properties of fasteners: nuts with specified proof load values fine pitch thread
4.1.32 BS EN 20898-7: 1995 Mechanical properties of fasteners: torsional test and minimum torques for bolts and screws with nominal diameters 1–10mm
4.1.33 BS EN ISO 4762: 2004 Metric hexagon socket head screws
4.1.34 BS EN ISO 10642: 2004 Hexagon socket countersunk head screws
4.1.35 BS4827 ISO metric screw threads, miniature series
4.1.36 BS3643 ISO metric screw threads: constant pitch series
4.1.37 BS EN ISO 228-1: 2003 Pipe threads where pressure-tight joints are not made on the threads
4.1.38 ISO pipe threads, tapered: basic sizes
4.1.39 British Standard Whitworth (BSW) bolts and nuts
4.1.40 British Standard Fine (BSF) bolts and nuts
4.1.41 ISO unified precision internal screw threads: coarse series (UNC)
4.1.42 ISO unified precision external screw threads: coarse series (UNC)
4.1.43 ISO unified precision internal screw threads: fine series (UNF)
4.1.44 ISO unified precision external screw threads: fine series (UNF)
4.1.45 British Association thread form
4.1.46 BA internal and external screw threads
4.1.47 BA threads: tapping and clearance drills
4.1.48 ISO metric tapping and clearance drills, coarse thread series
4.1.49 ISO metric tapping and clearance drills, fine thread series
4.1.50 ISO unified tapping and clearance drills, coarse thread series
4.1.51 ISO unified tapping and clearance drills, fine thread series
4.1.52 ISO metric tapping and clearance drills, miniature series
4.1.53 BSW threads, tapping and clearance drills
4.1.54 BSF threads, tapping and clearance drills
4.1.55 Plain washers, bright: metric series
4.1.56 Plain washers, black: metric series
4.1.57 Friction locking devices
4.1.58 Positive locking devices
4.1.59 Single coil square section spring washers: metric series, type A
4.1.60 Single coil rectangular section spring washers: metric series, types B and BP
4.1.61 Double coil rectangular section spring washers: metric series, type D
4.1.62 Toothed lock washers metric
4.1.63 Serrated lock washers, metric
4.1.64 ISO metric crinkle washers: general engineering
4.1.65 T-slot profiles
4.1.66 Dimensions of T-bolts and T-nuts
4.1.67 Dimensions of tenons for T-slots
4.2 Riveted joints
4.2.1 Typical rivet heads and shanks
4.2.2 Typical riveted lap joints
4.2.3 Typical riveted butt joints
4.2.4 Proportions for hole diameter and rivet length
4.2.5 Cold forged snap head rivets
4.2.6 Hot forged snap head rivets
4.2.7 Tentative range of nominal lengths associated with shank diameters
4.2.8 POP® rivets
4.2.9 POP® range guide
4.2.10 Good fastening practice
4.2.11 Selection of POP® (or blind) rivets
4.2.12 Design guidelines
4.2.13 POP® ‘F’ series
4.2.14 Open type aluminium 3.5% magnesium alloy
4.2.15 Open type carbon steel
4.2.16 Closed end type aluminium 5% magnesium alloy
4.2.17 Blind rivet nuts
4.2.18 POP® Nut Threaded Inserts: application
4.2.19 POP® Nut Threaded inserts: installation
4.2.20 POP® Nut: steel
4.3 Self-secured joints
4.3.1 Self-secured joints
4.3.2 Allowances for self-secured joints
4.4 Miscellaneous fasteners
4.4.1 Taper pins, unhardened
4.4.2 Circlips, external: metric series
4.4.3 Circlips, internal: metric series
4.5 Adhesive bonding of metals
4.5.1 Anaerobic adhesives
4.5.2 Adhesives cured by ultraviolet light
4.5.3 Adhesives cured by anionic reaction (cyanocrylates)
4.5.4 Adhesives cured with activator systems (modified acrylics)
4.5.5 Adhesives cured by ambient moisture
4.5.6 Epoxy adhesives
4.5.7 Redux process
4.5.8 Bonded joints

Chapter 5: Power Transmission
5.1 Power transmission: gear drives
5.1.1 Some typical gear drives
5.1.2 Simple spur gear trains
5.1.3 Compound spur gear train
5.1.4 The involute curve
5.1.5 Basic gear tooth geometry
5.1.6 Gear tooth pitch
5.1.7 Gear tooth height
5.1.8 Standard gear tooth elements (in.)
5.1.9 Fine pitch gear tooth elements (in.)
5.1.10 Standard stub gear tooth elements (in.)
5.1.11 Standard gear tooth elements (metric)
5.1.12 Letter symbols for gear dimensions and calculations
5.1.13 Basic spur gear calculations
5.1.14 Basic helical gear equations
5.1.15 Miscellaneous gear equations
5.1.16 Straight bevel gear nomenclature
5.1.17 Worm and worm wheel nomenclature
5.2 Power transmission: belt drives
5.2.1 Simple flat-belt drives
5.2.2 Compound flat-belt drive
5.2.3 Typical belt tensioning devices
5.2.4 Typical V-belt and synchronous-belt drive applications
5.2.5 ULTRAFLEX® narrow-section wrapped V-belts
5.2.6 FO®-Z heavy-duty cogged raw edge V-Belts
5.2.7 MULTIFLEX® classical-section wrapped V-belts
5.2.8 MULTIBELT banded V-belts
5.2.9 V-belt pulleys complying with BS 3790 and DIN standard 2211 for FO®-Z and ULTRFLEX® belts. Rz xx refers to surface roughness
5.2.10 V-belt pulleys complying with DIN standard 2217 part 1 for FO®-Z and MULTIFLEX® belts
5.2.11 Deep-groove pulleys
5.2.12 Synchronous-belt drives: introduction
5.2.13 Synchronous belt drives: belt types and sizes
5.2.14 Synchronous belt drives: pulleys
5.2.15 SYNCHROBELT® HTD
5.2.16 SYNCHROBELT® HTD synchronous (toothed) belts: tooth profiles
5.2.17 Synchronous (toothed) belts: length measurement
5.2.18 SYNCHROBELT® HTD toothed pulleys: preferred sizes
5.3 Power transmission: Chain drives
5.3.1 Chain performance
5.3.2 Wear factors
5.3.3 Chain types
5.3.4 International standards
5.3.5 Standards reference guide
5.3.6 Advantages of chain drives
5.3.7 Chain selection
5.3.8 Sprocket and chain compatibility
5.3.9 Drive layout
5.3.10 Selection method
5.3.11 Rating chart construction
5.3.12 European chain rating chart
5.3.13 ANSI rating chart
5.3.14 Chain suspension force
5.3.15 Lubrication
5.3.16 Lubricating methods
5.3.17 Lifting applications
5.3.18 ANSI Xtra range
5.3.19 Influences on chain life
5.3.20 Chain extension
5.3.21 Matching of chain
5.3.22 To measure chain wear
5.3.23 Repair and replacement
5.3.24 Chain adjustment
5.3.25 Design ideas
5.3.26 Table of PCD factors
5.3.27 Simple point to point drives: Example one
5.3.28 Simple point to point drives: Example two
5.3.29 Simple point to point drives: Example three
5.3.30 Safety warnings
5.4 Power transmission: shafts
5.4.1 Square and rectangular parallel keys, metric series
5.4.2 Dimensions and tolerances for square and rectangular parallel keys
5.4.3 Square and rectangular taper keys, metric series
5.4.4 Dimensions and tolerances for square and rectangular taper keys
5.4.5 Woodruff keys and keyways, metric series
5.4.6 Dimensions and tolerances for Woodruff keys
5.4.7 Shaft ends types: general relationships
5.4.8 Dimensions and tolerances of cylindrical shaft ends, long and short series
5.4.9 Dimensions of conical shaft ends with parallel keys, long series
5.4.10 Dimensions of conical shaft ends with diameters above 220 mm with the keyway parallel to the shaft surface, long series
5.4.11 Dimensions of conical shaft ends with parallel keys, short series
5.4.12 Transmissible torque values
5.4.13 Straight-sided splines for cylindrical shafts, metric
5.5 Tapers
5.5.1 Self-holding Morse and metric 5% tapers
5.5.2 Tapers for spindle noses
5.5.3 Tapers for tool shanks
5.5.4 Tool shank collars
5.5.5 Bridgeport R8 taper
5.6 Fluid power transmission systems
5.6.1 A typical pneumatic system
5.6.2 A typical hydraulic system
5.6.3 Air compressor types
5.6.4 Hydraulic pumps
5.6.5 Actuators (linear)
5.6.6 Actuators (rotary)
5.6.7 Hybrid actuator systems
5.6.8 Symbols for fluid power systems
5.6.9 Fluid power transmission design data (general formulae)
5.6.10 Fluid power transmission design data (hydraulic cylinders)
5.6.11 Fluid power transmission design data (hydraulic pipes and hoses)
5.6.12 Fluid power transmission design data (hydraulic fluids, seals and contamination control)
5.6.13 Fluid power transmission design data (hydraulic accumulators)
5.6.14 Fluid power transmission design data (hydraulic cooling and heating)
5.6.15 Fluid power transmission design data (pneumatic valve flow)
5.6.16 Fluid power transmission design data (pneumatic cylinders)
5.6.17 Fluid power transmission design data (seals, filtration and lubrication)
5.6.18 Fluid power transmission design data (air compressors)
5.6.19 Fluid power transmission design data (tables and conversion factors in pneumatics)
5.6.20 Guideline documents

Chapter 6: Engineering Materials
6.1 Mechanical properties
6.1.1 Tensile strength
6.1.2 Compressive strength
6.1.3 Shear strength
6.1.4 Toughness: impact resistance
6.1.5 Elasticity
6.1.6 Plasticity
6.1.7 Ductility
6.1.8 Malleability
6.1.9 Hardness
6.1.10 Tensile test
6.1.11 Interpretation of a tensile test: material showing a yield point
6.1.12 Interpretation of a tensile test: proof stress
6.1.13 Interpretation of a tensile test: secant modulus
6.1.14 Impact testing for toughness: Izod test
6.1.15 Impact testing for toughness: Charpy test
6.1.16 Interpretation of impact test results
6.1.17 Brinell hardness test
6.1.18 Vickers hardness test
6.1.19 Rockwell hardness test
6.1.20 Rockwell superficial hardness test
6.1.21 Comparative hardness scales
6.2 Ferrous metals and alloys
6.2.1 Ferrous metals: plain carbon steels
6.2.2 Effect of carbon content on the composition, properties and uses of plain carbon steels
6.2.3 Ferrous metals: alloying elements
6.2.4 British standards relating to ferrous metals
6.2.5 Some typical steels and their applications
6.2.6 Some typical tool steels
6.2.7 Flake (grey), cast irons
6.2.8 BS EN 1561: 1997 Grey cast irons
6.2.9 Malleable cast irons
6.2.10 Spheroidal graphite cast irons
6.2.11 Alloy cast irons
6.2.12 Composition, properties and uses of some typical cast irons
6.3 Non-ferrous metals and alloys
6.3.1 Non-ferrous metals and alloys – introduction
6.3.2 High copper content alloys
6.3.3 Wrought copper and copper alloys: condition code
6.3.4 British Standards relating copper and copper alloys
6.3.5 Copper and copper alloy rods and sections
6.3.6 Wrought copper and copper alloys
6.3.7 Wrought copper and copper alloys
6.3.8 Copper sheet, strip and foil
6.3.9 Brass sheet, strip and foil: binary alloys of copper and zinc
6.3.10 Brass sheet, strip and foil: special alloys and leaded brasses
6.3.11 Phosphor bronze sheet, strip and foil
6.3.12 Aluminium bronze alloys – introduction
6.3.13 Aluminium bronze sheet, strip and foil
6.3.14 Copper–nickel (cupro-nickel) sheet, strip and foil
6.3.15 Nickel–silver sheet, strip and foil
6.3.16(a) Miscellaneous wrought copper alloys
6.3.16(b) Miscellaneous wrought copper alloys
6.3.17(a) Copper alloys for casting: group A
6.3.17(b) Further copper alloys for casting: group A
6.3.18(a) Copper alloys for casting: group B
6.3.18(b) Further copper alloys for casting: group B
6.3.19(a) Copper alloys for casting: group C
6.3.19(b) Further copper alloys for casting: group C
6.3.20 Copper alloys for casting: typical properties and hardness values
6.3.21 Aluminium and aluminium alloys
6.3.22 British Standards
6.3.23 Unalloyed aluminium plate, sheet and strip
6.3.24 Aluminium alloy plate, sheet and strip: non-heat-treatable
6.3.25 Aluminium alloy plate, sheet and strip: heat-treatable
6.3.26 Aluminium and aluminium alloy bars, extruded tube and sections for general engineering: non-heat-treatable
6.3.27 Aluminium alloy bars, extruded tube and sections for general engineering: heat-treatable
6.3.28 Aluminium alloy castings, group A: general purpose
6.3.29 Aluminium alloy castings, group B: special purpose
6.3.30 Aluminium alloy castings, group C: special purpose and of limited application
6.3.31 Aluminium alloy castings: mechanical properties
6.3.32 BS EN 29453: 1993
6.3.33 Typical uses of soft solders
6.3.34 Silver soldering (hard soldering)
6.3.35 Group AG: silver brazing filler metals
6.4 Metallic material sizes
6.4.1 Metallic material sizes: introduction to BS 6722: 1986
6.4.2 Recommended diameters of wires, metric
6.4.3 Recommended dimensions for bar and flat products
6.4.4 Recommended widths and lengths of flat products
6.4.5 Mass of metric round and square bars
6.4.6 Hexagon bar sizes for screwed fasteners, metric
6.4.7 Gauge sizes and equivalents
6.5 Polymeric (plastic) materials
6.5.1 Polymeric (plastics) materials – introduction
6.5.2 Some important thermosetting polymers
6.5.3 Some important thermoplastic polymers

Chapter 7: Linear and Geometric Tolerancing of Dimensions
7.1 Linear tolerancing
7.1.1 Limits and fits
7.1.2 Classes of fit
7.1.3 Accuracy
7.2 Standard systems of limits and fits (introduction)
7.2.1 Application of tables of limits and fits
7.2.2 Selection of tolerance grades
7.3 Geometric tolerancing
7.3.1 Geometrical tolerance (principles)
7.3.2 Tolerance frame
7.3.3 Geometrical tolerance
7.3.4 Tolerance zone
7.3.5 Geometrical reference frame
7.3.6 Applications of geometrical tolerances
7.4 Virtual size
7.5 The economics of geometrical tolerancing

Chapter 8: Computer-Aided Engineering
8.1 Computer numerical control
8.1.1 Typical applications of computer numerical control
8.1.2 Advantages and limitations of CNC
8.1.3 Axes of control for machine tools
8.1.4 Control systems
8.1.5 Program terminology and format
8.1.6 Word (or letter) address format
8.1.7 Coded information
8.1.8 Data input
8.1.9 Tool length offsets: milling
8.1.10 Cutter diameter compensation: milling
8.1.11 Programming techniques: milling
8.1.12 Programming example: milling
8.1.13 Tool offsets: lathe
8.1.14 Tool nose radius compensation: lathe
8.1.15 Programming techniques: lathe
8.1.16 Programming example: lathe
8.1.17 Glossary of terms
8.2 Computer-aided design
8.2.1 An introduction to computer-aided design
8.2.2 CAD system hardware
8.2.3 CAD system software
8.2.4 Computer-aided design and manufacture
8.2.5 Advantages and limitations of CAD
8.3 Industrial robots
8.3.1 An introduction to robotics
8.3.2 Robot control
8.3.3 Robot arm geometry

Appendix 1 BSI Standards: Sales Order and Enquiry Contacts
Appendix 2 Library Sets of British Standards in the UK
Appendix 3 Contributing Companies
Appendix 4 Useful References