The English System of Measurement Principles of EngineeringTM Lesson 6.4 – Quality Assurance Forging new generations of engineers Project Lead The Way, Inc. Copyright 2007
The English System of Measurement
How precise do I need to be? We need to be able to accurately measure to the .001th .125
Decimal to Fraction Conversions .125 = 1/8” .250 = 1/4” .375 = 3/8” .500 = 1/2” .625 = 5/8” .750 = 3/4” .875 = 7/8” 1. = 1” .0625 = 1/16” .1875 = 3/16” .3125 = 5/16” .4375 = 7/16” .5625 = 9/16” .6875 = 11/16” .8125 = 13/16” .9375 = 15/16”
Tools used in Precision Measurement Gage Blocks: These are used throughout industry as primary standards and have accuracy to a few millionths of an inch.
Gage Blocks
Micrometers Sleeve Ratchet Stop Thimble
Dial Caliper
Dial Indicators