b'REAMER RUNDOWNA little knowledge about key subjects goes a long way when shopping for a reaming tool.By William LeventonI f you want better holes than a drill can pro-vide, youre probably in the market for a reamer, a rotary cutting tool used to en-large and accurately finish holes made by other means. Before beginning the search for a reamer, however, shops should become knowledgeable in certain areas, such as avail-able options, the information needed by po-tential suppliers and recent developments that might meet needs better than conventional alternatives.In some situations, it even can pay to take a step back and find out whether a reamer is nec-essary for a holemaking application.Sometimes, the first thing we look at is whether we can hold (the tolerance) the cus-tomer wants with a drilling operation, said Craig Ewing, national drilling product special-ist at Iscar Metals Inc. in Arlington, Texas. If the tolerance is not too tight, there are a lot of things that can be done in the drilling process that will often produce an accurate hole.He said drilling can hold tolerances now that in the past could be achieved only by reaming.With the old high-speed drilling, you were lucky to get an IT10 tolerance, Ewing said. But today, we will typically drill from an IT8 to an IT9 tolerance. If you want to go tighter than IT8, you need to go to reaming, which easily can attain an IT7 tolerance and in some cases Bayo T-Ream offers interchangeable solid-carbide heads for high-speed reaming applications. A through-the-tool coolant system delivers lubrication directly to each cutting edge.18SEPTEMBER 2021Reaming.indd 18 8/17/21 3:05 PM'