3rd Edition

Fundamentals of Machine Elements SI Version

    632 Pages 466 B/W Illustrations
    by CRC Press

    New and Improved SI Edition—Uses SI Units Exclusively in the Text

    Adapting to the changing nature of the engineering profession, this third edition of Fundamentals of Machine Elements aggressively delves into the fundamentals and design of machine elements with an SI version. This latest edition includes a plethora of pedagogy, providing a greater understanding of theory and design.

    Significantly Enhanced and Fully Illustrated

    The material has been organized to aid students of all levels in design synthesis and analysis approaches, to provide guidance through design procedures for synthesis issues, and to expose readers to a wide variety of machine elements. Each chapter contains a quote and photograph related to the chapter as well as case studies, examples, design procedures, an abstract, list of symbols and subscripts, recommended readings, a summary of equations, and end-of-chapter problems.

    What’s New in the Third Edition:

    • Covers life cycle engineering
    • Provides a description of the hardness and common hardness tests
    • Offers an inclusion of flat groove stress concentration factors
    • Adds the staircase method for determining endurance limits and includes Haigh diagrams to show the effects of mean stress
    • Discusses typical surface finishes in machine elements and manufacturing processes used to produce them
    • Presents a new treatment of spline, pin, and retaining ring design, and a new section on the design of shaft couplings
    • Reflects the latest International Standards Organization standards
    • Simplifies the geometry factors for bevel gears
    • Includes a design synthesis approach for worm gears
    • Expands the discussion of fasteners and welds
    • Discusses the importance of the heat affected zone for weld quality
    • Describes the classes of welds and their analysis methods
    • Considers gas springs and wave springs
    • Contains the latest standards and manufacturer’s recommendations on belt design, chains, and wire ropes

    The text also expands the appendices to include a wide variety of material properties, geometry factors for fracture analysis, and new summaries of beam deflection.

    Part I — Fundamentals


    What is Design?

    Design of Mechanical Systems

    Design as a Multidisciplinary Endeavor

    Design of Machine Elements

    Computers in Design

    Catalogs and Vendors


    Unit Checks

    Significant Figures


    Load, Stress, and Strain


    Critical Section

    Load Classification and Sign Convention

    Support Reactions

    Static Equilibrium

    Free-Body Diagram

    Supported Beams

    Shear and Moment Diagrams


    Stress Element

    Stress Tensor

    Plane Stress

    Mohr’s Circle

    Three-Dimensional Stresses

    Octahedral Stresses


    Strain Tensor

    Plane Strain


    Introduction to Materials and Manufacturing


    Ductile and Brittle Materials

    Classification of Solid Materials

    Stress-Strain Diagrams

    Properties of Solid Materials

    Stress-Strain Relationships

    Two-Parameter Materials Charts

    Effects of Manufacturing


    Stresses and Strains


    Properties of Beam Cross Sections

    Normal Stress and Strain


    Bending Stress and Strain

    Transverse Shear Stress and Strain




    Moment-Curvature Relation

    Singularity Functions

    Method of Superposition

    Strain Energy

    Castigliano’s Theorem


    Failure Prediction for Static Loading


    Stress Concentration

    Fracture Mechanics

    Modes of Crack Growth

    Fracture Toughness

    Failure Prediction for Uniaxial Stress State

    Failure Prediction for Multiaxial Stress State


    Fatigue and Impact



    Cyclic Stresses

    Strain Life Theory of Fatigue

    Fatigue Strength

    Fatigue Regimes

    Stress Concentration Effects

    The Modified Endurance Limit

    Cumulative Damage

    Influence of Nonzero Mean Stress

    Influence of Multi-Axial Stress States

    Fracture Mechanics Approach to Fatigue

    Linear Impact Stresses and Deformations


    Lubrication, Friction, and Wear


    Surface Parameters

    Conformal and Nonconformal Surfaces

    Hertzian Contact

    Bearing Materials

    Lubricant Rheology

    Regimes of Lubrication




    Part II — Machine Elements



    Equilibrium Regimes

    Concentrically Loaded Columns

    End Conditions

    Euler’s Buckling Criterion

    Johnson’s Buckling Criterion

    AISC Criteria

    Eccentrically Loaded Columns


    Stresses and Deformations in Cylinders


    Tolerances and Fits

    Pressurization Effects

    Rotational Effects

    Press Fits

    Shrink Fits


    Shafting and Associated Parts


    Design of Shafts for Static Loading

    Fatigue Design of Shafts

    Additional Shaft Design Considerations

    Critical Speed of Rotating Shafts

    Keys, Roll Pins, Splines and Set Screws

    Retaining Rings and Pins




    Hydrodynamic and Hydrostatic Bearings


    The Reynolds Equation

    Thrust Slider Bearings

    Journal Slider Bearings

    Squeeze Film Bearings

    Hydrostatic Bearings


    Rolling-Element Bearings


    Historical Overview

    Bearing Types and Selection




    Static Load Distribution

    Elastohydrodynamic Lubrication

    Fatigue Life

    Variable Loading


    General Gear Theory; Spur Gears


    Types of Gears

    Gear Geometry

    Gear Ratio

    Contact Ratio and Gear Velocity

    Tooth Thickness and Backlash

    Gear Trains

    Gear Manufacture and Quality

    Gear Materials

    Loads Acting on a Gear Tooth

    Bending Stresses in Gear Teeth

    Contact Stresses in Gear Teeth

    Elastohydrodynamic Film Thickness

    Gear Design Synthesis


    Helical, Bevel, and Worm Gears


    Helical Gears

    Bevel Gears

    Worm Gears


    Fasteners, Connections, and Power Screws


    Thread Terminology, Classification, and Designation

    Power Screws

    Threaded Fasteners

    Riveted Fasteners

    Welded, Brazed, and Soldered Joints

    Adhesive Bonding

    Integrated Snap Fasteners




    Spring Materials

    Helical Compression Springs

    Helical Extension Springs

    Helical Torsion Springs

    Leaf Springs

    Gas Springs

    Belleville Springs

    Wave Springs


    Brakes and Clutches


    Thermal Considerations

    Thrust Pad Clutches and Brakes

    Cone Clutches and Brakes

    Block or Short-Shoe Brakes

    Long-Shoe, Internal, Expanding Rim Brakes

    Long-Shoe, External, Contracting Rim Brakes

    Symmetrically Loaded Pivot-Shoe Brakes

    Band Brakes

    Slip Clutches


    Flexible Machine Elements


    Flat Belts

    Synchronous Belts


    Wire Ropes

    Rolling Chains





    Steven R. Schmid received his B.S. in mechanical engineering from the Illinois Institute of Technology in 1986. He earned his master’s degree from Northwestern University in 1989 and his Ph.D. in 1993, both in mechanical engineering. In 1993 he joined the faculty at the University of Notre Dame, where he is a professor of aerospace and mechanical engineering, teaching and conducting research in design and manufacturing. Dr. Schmid holds professional engineering (P.E.) and certified manufacturing engineer (C.Mfg.E.) licenses. He was awarded the ASME Foundation Swanson Fellowship in 2012, and is a Fellow of the American Society of Mechanical Engineers.

    Bernard J. Hamrock joined the staff of Ohio State University as a professor of mechanical engineering in 1985 and is now professor emeritus. Before joining Ohio State University he spent 18 years as a research consultant in the Tribology Branch of the NASA Lewis Research Center in Cleveland, Ohio. He received his Ph.D. and doctor of engineering degrees from the University of Leeds, England. His research has resulted in a book, three separate chapters for handbooks, and over 150 archival publications. He has received several awards including the 2000 Mayo D. Hersey Award from the American Society of Mechanical Engineers.

    Bo O. Jacobson received his Ph.D. and D.Sc. degrees from Lund University in Sweden. From 1973 until 1987 he was professor of machine elements at Luleå University of Technology in Sweden. In 1987 he joined SKF Engineering & Research Centre in the Netherlands, while retaining a professorship at Chalmers University from 1987 to 1991 and at Luleå University of Technology from 1992 to 1997. In 1997 he was appointed professor of machine elements at Lund University, Sweden. He has published four compendia used at Swedish universities, and has contributed more than 100 archival publications. His awards include the Tribology Gold Medal received in 1997.