TechFront New Developments in Manufacturing and Technology
Tooling Choices Lead to Thread Milling Solutions
“W
hen most people talk about the question of tool life, they’re referencing extending the time of use of a particular tool. It can be more help- ful to take a look at the big picture and examine the question of tool life from a technological perspective,” said Jeff Dei, president, Carmex Precision Tools LLC (Richfield, WI). “In effect, if tool life is too short, you might be using the wrong tool. For instance, over the years, many of our customers have come to us because they were regularly breaking taps. By altering the approach from tapping to thread milling, they were able to derive a better result and eliminate the question of tap life. “Even in cases where the customer has opted for thread milling, however, it is essential that the tool selected meet the highest quality standards in order to ensure the best results and the longest life,” said Dei, citing the example of a high-precision specialty shop Apex CNC Swiss located in western Pennsylvania. Production capabili- ties of the latest generation of Swiss-style machines has necessitated a new generation of tools capable of standing up to the rigors of high-speed, high-pressure coolant and high-volume production. Apex CNC Swiss has to meet the challenges of high-precision complex parts machined in hard materials and exotic alloys. “One of the challenges facing Apex CNC Swiss involved an electronic circuit board standoff in 303 stainless which was machined on a Star SR-20RIII machine,” said Chuck Fluharty, co-owner. The 0.180" (4.6-mm) deep hole being threaded required a 0–80 thread. Using a competitor’s tool, between 200–300 parts were machined before tool failure. When the manufacturer’s technical support was contacted, Apex was advised that it was normal. Apex then searched for a better
solution. When Apex switched to the Carmex mini mill-thread design, production soared to over 2000 parts, and they were able to do 500 additional parts in 17-4 stainless. “The advantage of longer tool life doesn’t stop with having to purchase fewer tools over time. Even more important, once we had established that we could trust the Carmex tool for longer production runs, we were able to spend less time
Parts are machined from hard materials by Apex using the latest thread milling tools from Carmex Precision Tools.
monitoring the machine and changing tools, and that resulted in even further savings, including untended operation up to four-hour cycles,” said Fluharty.
Another case of switching to thread milling involved a shop owner who was machining a critical part for a radar compo- nent. Made of titanium alloy 6 Al-4V, the part required 683 blind holes. Because of the tapping operation, his customer had to allow a tap deviance of 0.040" (1.0 mm) in depth to allow for the thread clearance. This meant that the holes had to go from a depth of 0.150–0.190" (3.8–4.8 mm). The
April 2013 |
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