Cutting fluid cuts machining time.

Cutting fluid cuts machining time

Egli Machine Co, Sidney, NY, is a contract manufacturer of precision machined components and assemblies for electronic equipment. They cannot tolerate lubricant or cutting-oil related problems when working to extremely close tolerances. One challenge is machining injection molds for electronic-connector plugs.

"These molds," explains Henry Egli, chairman, "are machined from A6 tool steel and require drilling many small holes with a tolerance of 0.0002", the outer limits of machining. We had been using a water-soluble cutting fluid because it was easy to wipe off the parts. Our operators were constantly miking parts, but our drills were wearing down and even a slight amount of wear or score would scrap a part. Operators were also experiencing skin problems from the fluid and the solvent required when wiping parts.

"Switching from a water-soluble fluid to a mineral-base fluid actually came about as something of a quirk. Normally, when a water-soluble fluid isn't working right, you try another one, but changing to a mineral oil is a real switch. Yet, with that change we were able to eliminate skin problems, improve tool life and finish, hold tolerances longer, and reduce machining time as much as 30 percent."

The changeover resulted from calling in their local lubricant supplier, Mirabito Fuel Group, the Mobil oil distributor in Sidney, to try to consolidate their lubricant inventory. By following machine-builder recommendations, their inventory had grown to the point where it was difficult to keep track of them all and avoid a mismatch. Out of this evaluation came suggestions that helped cut their inventory in half and also the recommendation to use a mineral-oil-based fluid, Mobilmet Nu.

This heavy-duty, medium viscosity fluid is nonstaining and meets the antiweld and lubricity requirements of the most severe machining operations. Because it can be used on the cutting side as well as the lubricating side of the machine, any leakage is no longer a problem.

Reports Egli, "Although our machine operators were skeptical at first, they began to see immediate improvements. First, in finish quality--50-percent less polishing time --and then tool life improved drastically, saving us more in tool replacement and downtime. Drills held accurate diameters much longer and we didn't have to make any tool adjustments when changing from drilling to boring."

Besides the 30-percent reduction in machining time, they no longer worry about fluid concentration or disposal. Water-soluble oil required changing every six months, but now the fluid can be passed through a filter and used over and over.

Adds Egli, "Our operators will sometimes revert back to the old coolant on occasional high-production runs because of the ease with which it wipes off for tolerance checks, but we are looking into a cleaning system that strips the mineral oil with equal ease. Looking down the road, we hope to completely eliminate soluble oils."