by Jock Dempsey
Machinery's Handbook has always been one of my favorite references.
For anyone in the mechanical trades it is an indispensable source of knowledge, facts and figures.
It includes everything from volume and beam stress formulas to the periodic table and how to apply SI metric standards.
Need to know the density of oak or mahogany, or how about the constituents of forging brass? Machinery's has it all!
Machinery's has long been subtitled,
"A Reference for the Mechanical Engineer, Draftsman, Toolmaker and Machinist".
Unofficially it has been known as the Machinist's Bible and almost every machinist's and many mechanics tool chests have had a special top center drawer especially for Machinery's Handbook
Machinery's is so much a part of the engineering culture in North America that virtually every curriculum in metalworking and engineering has a required course on how to use Machinery's Handbook.
Sadly many of these students do not learn to appreciate this solid gold reference and the used book market is often flooded with virtually new copies of Machinery's Handbook.
As a basic reference it is as important to me as a good unabridged dictionary.
Change comes slow to such an encyclopedic reference published for nearly a century.
New editions have been published every four years to keep up with changes in knowledge and technology.
You can pick up a 5th Edition of Machinery's Handbook and it looks very similar to the 27th edition.
From the 10th edition up they look almost identical.
In fact many of the original articles and data that have not changed are still in this newest edition.
However, technology does change and what was once important industrial practice is now the archaic.
The 27th edition has some of the biggest changes in its 90 year history.
Most notably the organization and indexing.
Besides the normal keyword index there are now additional indexes for Standards (11 pages) and for Interactive Equations (5 pages).
Each major section of the book (divided at the thumb tabs) now has a table of contents.
This makes the book much easier to navigate by subject.
Many sections have been completely rewritten and illustrated.
Old diagrams that were a tad raggedy for the modern era have been redrawn in CAD and are much clearer.
The welding section includes details on MIG pipe welding and LASER cutting and welding with wonderful clear line illustrations.
Of course major rewrites often invite new errors. See An Error below.
I was also disappointed that articles on vibratory finishing and tumbling are absent from the section on finishing.
But there are many new technologies that need coverage and editors are often forced to make hard decisions.
For a couple decades the end papers were used as a "Ready Reference Index" or quick index.
Then they reverted back to plain.
The new 27th edition has handy Conversion Factors charts from Cosworth.
The front (at left) has Area and Volume conversions, the back Force, Pressure, Stress, Energy and Mass. Click for detail.
Perhaps this is a sign that the engineering world is recognizing that there may always be more than one standard of measurement and that conversions will be with us for a long time.
Thumb Tabs have been one of Machinery's constants for most regular users.
You could pick up any edition and go to a familiar topic.
New tabs are part of the reorganization and new indexing scheme.
Some are familiar, some combine old topics.
For daily users the new tabs and organization may take some getting used to. Such is progress.
27th Ed. Thumb Tab Topics (12)
Math & Mechanics
Properties of Materials
A Minor Error: No major new edition is perfect. While charting the changes in Machinery's for our
collective review of Machinery's Handbook for blacksmiths, I noticed a rather glaring error in the section on welding.
The first sentence reads:
Welding of metals requires that they be heated to a molten state so that they fuse together. . . .
In fact metals can be welded at room temperature in a vacuum and are commonly welded at much less than the melting point while in the plastic state.
Although the blacksmith's solid state forge welding may be considered archaic as an industrial process,
there were several pages on the subject in the first dozen editions of Machinery's and it was still defined as a process up through the 18th Edition.
Solid state welding is still a production process in making pipe, tubing and clad metals.
Besides being an error this reflects the decline of the primary metal industries in the United States.
From a peak of 20 pages referring to forging in the 1956 15th edition of Machinery's there are now none.
NOTE: These pages are restored in the CD-ROM version as additional materials.
Further Comment: This error (more of omission than fact) goes back as far as the 17th edition (maybe 16th) when the article on welding was re-written to place less emphasis on forge welding.
The original welding article describes the forge welding process as occurring when the metal becomes "soft and plastic" (5th maybe 1st through 15th edition).
This is correct.
This new edition has a lot of changes that long time users may not like or will need to get used to.
For new users this is still the gold standard reference of the mechanical and engineering trades.
Even though I have had newer editions than my original 1968 18th edition I have always referred to that old edition.
However, just browsing through this new edition I see many new items of value that will keep this one on my desk.
A great new edition.
Published by: Industrial Press
200 Madison Avenue
New York, NY 10016
Suggested Retail Price $85.00 USD, Large print edition $99.95, CD-ROM $89.95
ISBN 0-8311-2700-7 and 0-8311-2711-2 (large print)