Limits to Mea's 12 Workbook 11. Ali is a glass lens cutter. He uses a micrometre to measure the glass. In order to fit a particular glass frame, a lens needs to have a thickness of 0.8 mm + 0.005 mm. a) What is the tolerance? b) What are the maximum and minimum acceptable lens thicknesses? 12. Kelsey is a welder. She needs to preheat a section of steel before welding, to reduce the risk of cracking as the steel cools. She needs to heat the steel to between 225OF and 275.F. a) What is the temperature tolerance? b) What is the nominal temperature? ty of a weld can by checking for stortions, and r by destructive determine the c) Write the acceptable temperature range in four different ways. formance under ditions