24-08-2019, 05:22 AM
The conversion 25.4 mm to inch is very accurate and all that has to be remembered. The most basic pocket calculator, phone etc will multiply. For the amateur doing little work micrometers in either suffice. Old inch ones often very cheap. Many own cheap digital verniers which can be set to give an instant conversion, although these do need a battery.( Personally for direct measurement I prefer the direct reading ones as keeps the brain alert and you see exactly what measuring, and less inclined to assume excessive accuracy. A quality 8 inch vernier calliper probably the most useful tool acquired although care necessary. Some elderly tote a magnifying glass! Saves having to carry an assortment of specs). A metric man will find totting up multiples of .025 inch on inch mics and verniers a bit strange.
Distinction between mm and cm needs care. I have seen tolerances in motor manuals which have confused. A micron (millionth of a metre) is less than half a ten thousandth inch. Can be confusing to calculate if you left school long ago. (microns used for ball bearing clearances and tolerances)
When used to working to thousands of inch, dial gauges, micrometers etc in .001 of a cm, 01 of a mm tend to lure into excessive exactness.
The 12 inches in a foot and yard likely more stressful to others.
Distinction between mm and cm needs care. I have seen tolerances in motor manuals which have confused. A micron (millionth of a metre) is less than half a ten thousandth inch. Can be confusing to calculate if you left school long ago. (microns used for ball bearing clearances and tolerances)
When used to working to thousands of inch, dial gauges, micrometers etc in .001 of a cm, 01 of a mm tend to lure into excessive exactness.
The 12 inches in a foot and yard likely more stressful to others.