Degarmo S Materials And Processes In Manufacturing

Why Most People Approach Degarmo Backwards

The book is called Materials and Processes in Manufacturing, and most people treat it like a reference manual they crack open when they get stuck on a quiz or a work problem. That is not how you get value from it. The book works best when you read it alongside whatever process you are actually trying to understand. Pick a chapter, work through the concepts, then go look at the real thing. The gap between reading about casting and standing in front of a sand mold pour is real. The book fills in the vocabulary for what you see, which is a completely different cognitive experience than memorizing definitions for an exam. I picked up the tenth edition because a supplier kept sending me stamped parts that cracked at the bend line. I should have just called the vendor and asked about their material spec, but instead I went straight to the forming and sheet metal chapters. The answer was in a section I had skimmed over before: the distinction between elastic and plastic deformation in the context of springback and how grain orientation relative to the bend axis changes everything. It turned out they were using strip with the wrong grain flow direction and cutting blanks without accounting for it. Standard fix was to specify a perpendicular grain orientation and allow for the springback angle in the tooling. The book did not hand me that solution directly. It gave me the framework to understand what was going wrong and where to look next.

Degarmo S Materials And Processes In Manufacturing

Full title is Materials and Processes in Manufacturing by John T. Broke, Leland P. Buccino, and Ronald G. Smith, building on the original work by James A. Schey and Serope Degarmo. The current editions are typically published by Wiley and they sit somewhere between a textbook and a practitioner's handbook. You will find chapters on casting, forging, extrusion, rolling, powder metallurgy, welding, machining, polymers, composites, and ceramics, plus substantial sections on metrology, quality control, and production systems. The book is not organized by industry. It is organized by process type, which is useful if you need to compare how the same material behaves under different forming methods. It is less useful if you are trying to find a quick lookup for a specific alloy system. The materials sections are integrated into each process chapter rather than collected in one big reference section, which means you will find discussions of steel solidification in the casting chapter and then a different discussion of the same steel in the forging chapter. That repetition is intentional. The material behavior is not constant across processes because temperature, strain rate, and thermomechanical history all change the outcome. I keep a dog-eared copy on my desk. Not because I read it cover to cover. Because I know where to find the diagrams on TTT curves, the tables for cutting tool materials, and the equations for bending force estimation. The diagrams are better than most online references. The equations are practical but simplified, which is both a strength and a weakness. They give you a starting point. They do not replace process simulation software for anything that matters at scale.

How to Actually Use This Book

Start by identifying the process chain for the part you are working on. A single component can go through casting, heat treatment, machining, surface finishing, and assembly. Each step is covered in a different chapter. The book will feel disjointed unless you trace the part through the sequence yourself. Draw the flow on a whiteboard. Look up each step. Connect the material changes across steps. The tables in the book are where most people miss the signal. They look at yield strength numbers and forget that those numbers come with conditions. Temperature, strain rate, and prior processing history all shift the values. I had a case where a customer specification called for a certain tensile strength in a forged aluminum component, and the supplier hit the number on a test bar but the part still failed in service. The issue was that the test bar had been machined from a different location in the forging than the critical section of the actual part. The directional properties from the forging flow were different at that location. The book covers this in the forging and material property chapters but you have to connect the dots. It does not hold your hand through it. When you are studying welding, do not skip the heat affected zone sections. That is where everything falls apart in practice. The base metal properties change in the zone next to the weld bead, and the book gives you the metallurgy behind why. Understanding that is what separates someone who just follows a Welding Procedure Specification from someone who can troubleshoot when the WPS does not produce good results on a particular joint configuration.

Common Pitfalls

The biggest mistake people make is treating the book as a complete guide to manufacturing. It is not. It covers traditional processes very well. It does not go deep on additive manufacturing beyond what is relevant to binder jetting and powder bed fusion in the context of materials behavior. If your work involves 3D printed metals, you need supplemental references. The book was written before additive manufacturing became a mainstream production consideration. Another issue is the numerical examples. They use English units in most editions, and while there are metric equivalents in some sections, the conversion is not always clean. I have seen students and engineers plug in metric values without converting the material property tables, which produce obviously wrong results. Always check the units. Every table header and every equation footnote. One time I calculated a cutting force for a turning operation using the specific energy values from the book and got a result that implied the motor would stall. The problem was that I had used the imperial specific energy value without converting it. The correct calculation used a much lower force. The book had the right number. I made the unit error. A third pitfall is assuming the process parameters in the book are universal. They are starting points. A book value for minimum bend radius in sheet metal depends on the specific alloy temper, thickness, and grain direction. The ranges given are typical, not absolute. If you use them as hard limits you will either overdesign your tooling or underestimate failure risk. I learned that the hard way with a 6061-T6 aluminum bracket. The book suggested a certain bend radius for the material group, and I followed it. The parts cracked on the second press brake run because the stock batch had a slightly different temper condition than what the table assumed. I ended up increasing the radius and adjusting the springback compensation. It cost us a small batch of scrap but it was cheaper than a tooling rework.

What the Book Gets Right That Other References Miss

The integration of materials science with process mechanics is the main thing. Most manufacturing books either lean too hard into the metallurgy and lose the shop floor relevance or they focus on machine settings and skip why the material behaves the way it does. Degarmo sits in the middle. You learn why a particular cooling rate in casting produces a different microstructure, and you also learn what that means for the final mechanical properties and machinability. That linkage is valuable. The section on tolerances and fits is another area where the book is practical. It does not just list tolerance grades. It explains how process capability relates to tolerance selection and what happens when you push a process beyond its natural variation. I have used that section when a design engineer specified a tolerance that was tighter than what the chosen manufacturing process could reliably hold. The book gave me the data to show the trade-off between tolerance tightness and cost, which is a conversation every manufacturing engineer has at some point.

Supplementary Reading

If you are working primarily in machining, pair the book with ASM Handbook Volume 16 on machining. The Degarmo coverage is solid for fundamentals but ASM goes deeper into tool geometries, coatings, and cutting fluid selection. For casting, the ASM Handbook Volume 15 on casting is a natural follow-up. For welding, Volume 6 on welding, brazing, and soldering is the standard reference that complements what the book covers. These are not replacements for the main text. They fill in the gaps where the book necessarily stays at a higher level. The book is available through Wiley, Amazon, and university bookstores. The latest edition is the tenth, published around 2019. Earlier editions are substantially similar in core content. The process descriptions and material property fundamentals do not change significantly between editions. If you are on a budget, a ninth or eighth edition will serve you nearly as well, especially if you are using it as a reference rather than a course textbook. The main differences between editions are updated figures, revised examples, and minor additions to sections on sustainability and advanced materials. I do not recommend reading it straight through unless you are taking a course. Skim the table of contents, find the chapters relevant to your current project, and work through those sections with a notebook. The book rewards active engagement. It does not reward passive highlighting. The diagrams and tables are where the useful information lives. Read around them, not past them.