Other minor differences are spelled out in the Y14.5 standard in paragraphs 1.6 and 2.3.ДЇinally, I should mention that our training is available in either system of units. One custom is that a number less than one millimeter is to be preceded by a zero (such as 0.5 mm) but a number less than one inch should not (such as.

Second, there are different customs to follow when displaying millimeters on a drawing than for inches. First, keep in mind that rounding error may occur. Obviously, dimensions and tolerances given in one system can be easily converted to the other, but several things need to be addressed when doing this. But other industries, such as the aircraft industry, continue to use inches, as do smaller suppliers and machine shops. many industries have made the complete changeover to metric (including the automotive industry). (WerenвЂ™t we all told back in the late 1970s that everything would soon be metric?) The millimeter is widely used by countries besides the United States, and within the U.S. This may be humorous to those companies that have always used inches and continue to do so. Customary units could equally well have been used without prejudice to the principles established.вЂќ Paragraph 1.1.2 phrases it this way: вЂњThe International System of Units (SI) is featured in this standard because SI units are expected to supersede United States (U.S.) customary units specified on engineering drawings. The technical standard ASME Y14.5M-1994 uses SI units (millimeters). The answer: It doesnвЂ™t really matter! The GD&T system works the same using inches or millimeters the only thing that changes is the number. When it comes to GD&T training, I am often asked which units of measurement are preferred.

Asme y14.5m vs asme y14.5