Similar to other types of cutting tools, offthe- shelf superabrasive tools are becoming commodity items. Application-specific PCD and polycrystalline cubic boron nitride specials are an exception, and CITCO Products, Chardon,

Ohio, is one toolmaker that produces such tools. Report by Alan Richter.

An end user going through an optimisation process may feel that his application is completely unique, but it’s likely that similarities exist with applications at other manufacturers. CITCO gathers case history information so when it needs to develop specials, that information can help determine what specific tool geometry and PCD or PCBN grade is appropriate based on similar applications, according to Ed Galen, sales manager for CITCO. “We do a lot of testing and database accumulation,” he added. Besides accumulating data about an end user’s workpiece material, toolholders and type of coolant – if any – being applied, a customer’s equipment capabilities play a major role in designing superabrasive specials. “In many cases, the equipment itself will dictate to a large extent what you can do with the tools,” Galen said. Purchasing or upgrading a machine tool or other piece of equipment to achieve the process requirements is typically not an option. “Usually, the customer says, ‘I’ve got this job, I want to run it on this piece of equipment and don’t tell me I need to buy a new piece of equipment,’” Galen said. If a machine isn’t capable of running at the required parameters, for example, or meeting tolerance specifications, CITCO will recommend a piece of equipment that should. “There have been cases where customers said they don’t want to do that, and then we say, ‘Sorry, we can’t help you.’” Galen said about half of end users switch from carbide to superabrasive tools to achieve their goals, often after testing other carbide tools because sometimes they’re trying to avoid costlier superabrasive tools or reduce tool costs even when a superabrasive tool can reduce their cost per part.

“We’ve found, in most cases, that if you can reduce cycle time or increase tool life by a relatively small percentage,” he said, “the cost of the tool doesn’t mean much of anything in the equation.” Combining multiple operations into a single superabrasive tool can result in a tooling solution with a high acquisition cost, but one that is cost effective when focusing on the cost to use. The percentage being saved to justify switching to a superabrasive special depends on the company and application, but Galen said the rule of thumb is 15%. “Some companies realise that a 5% savings on something that’s costing $20 million to produce is a huge saving,” he said, “but there are others that if they can’t show 15%, then it gets lost in the shuffle. Ninety-nine times out of a hundred 15% will catch somebody’s attention. If you’re under 10%, they’ll attribute it to luck.” Cost, however, isn’t the only factor when considering switching to an application specific superabrasive tool. In one application, CITCO replaced a carbide drill for creating a valve hole with a PCBN tipped drill with a K-land hone. The new drill reduced production costs by only 12%. The customer, however, was experiencing a quality problem with valves sticking, which was eliminated by switching to the slower-wearing PCBN drill.