Begin by dressing the grinding wheel. Next, look up the typical angles for the workpiece material, and then follow the steps in Figure A–2. Dip the tool in coolant frequently to keep it from overheating and annealing. Any discoloration on the bit indicates it may no longer be hardened. If this happens, consider starting over again from the beginning. Tool bit angles are not critical and most tools will cut material satisfactorily, just less effectively.Read more
What are the common methods for removing frozen or broken threaded fasteners?
Here are some approaches and cautions. Take the least destructive removal steps first. Often several steps are needed, like heat cycling, tapping and overnight penetrant. Be persistent and try alternatives. The choice of removal methods should take into consideration where the fastener was snapped
In this post, you will find the dimensions of R8 collet used in Bridgeport-style milling machine and 5C collet used in many lathes and indexing fixtures.Read more
In this post, you will find a chart providing the decimal-fraction equivalents that are most relevant to fractional-inch, letter and metric drill bit sizes (that is, 0 to 1 by 64ths).Read more
Unlike lathes, which have been known for thousands of years, milling machines are less than two hundred years old. Because they require much more power than hand-driven lathes, their introduction had to wait for the invention of industrial water and steam power. Also, all their mechanical components had to first be made available, such as accurately fitted slides, large castings to resist cutting forces, calibrated leadscrews and hardened steel cutting tools.Read more