Verify dimensions, alignments, and clearances of finished parts for conformance to specifications, using measuring instruments such as calipers, gauge blocks, micrometers, and dial indicators. Study blueprints, sketches, models, or specifications to plan sequences of operations for fabricating tools, dies, or assemblies. Set up and operate conventional or computer numerically controlled machine tools such as lathes, milling machines, and grinders to cut, bore, grind, or otherwise shape parts to prescribed dimensions and finishes. Visualize and compute dimensions, sizes, shapes, and tolerances of assemblies, based on specifications. Inspect finished dies for smoothness, contour conformity, and defects. Fit and assemble parts to make, repair, or modify dies, jigs, gauges, and tools, using machine tools and hand tools. Conduct test runs with completed tools or dies to ensure that parts meet specifications, making adjustments as necessary. Select metals to be used from a range of metals and alloys, based on properties such as hardness and heat tolerance. File, grind, shim, and adjust different parts to properly fit them together.