This is book is the accumulation of things I have learned over the last 40 years while working in industry, teaching, corporate training, and making mistakes. More and more shops and toolrooms are making the move to the metric system. Once adopted, it is easier to work with and cheaper to maintain. For those of you working in job shops as I have, the standards are constantly changing depending on who you are working for. This creates constant learning opportunities, if you want to call them that. This book is about what I have learned. Thank you for your interest and here is the first of many editions of "Machinist's Guide".