Partnering to effectively grind microdrills

END USER: Michigan Drill, (800) 234-5250, www.michigandrill.com.
CHALLENGE: Effectively produce M-42 and M-2 HSS microdrills.
SOLUTION: A 5-axis tool and cutter grinder coupled with CBN wheels.
SOLUTION PROVIDERS: Norton/Saint-Gobain Abrasives, (254) 918-2313, www.nortonindustrial.com; Unison Corp., (248) 544-9500, www.unisoncorp.com.

As the market for microscale cutting tools continues to grow, Michigan Drill’s Troy, Mich., facility identified a major demand for M-42 and M-2 HSS microdrills, specifically ones measuring 0.0059 ” to 0.020 ” in diameter. In addition to drills, the toolmaker, which has its primary manufacturing facility in Miami, Fla., produces reamers, endmills, taps and dies, as well as indexable, solid-carbide and carbide-tipped tools.

After approaching several companies to find a manufacturing solution, Michigan Drill partnered with Ferndale, Mich.-based Unison Corp. and Norton/Saint-Gobain Abrasives, Worcester, Mass. Unison provided the Model 2850 5-axis CNC tool and cutter grinder, and the toolmaker coupled the machine with Norton’s T2 vitrified-bond CBN and Univel-bond CBN wheels, along with a reinforced, sintered profiling diamond dress roll.

“Unison’s machine was definitely the most price-competitve,” said John Marion, site manager for Michigan Drill, “but, more than that, they are practically in my backyard. Their Ferndale facility is so close that some of their employees almost drive past our plant on the way to work. So, from both an economical and logistical standpoint, it was a no-brainer.”

Courtesy of Unison

John Marion, site manager for Michigan Drill, with the Unison Model 2850 5-axis CNC tool and cutter grinder that the toolmaker uses to produce HSS microdrills.

Unison has been building grinders for more than 50 years and serves numerous industries, including aerospace, medical, dental, automotive, off-highway, plastics and petrochemical. The Model 2850 has an online rotary wheel dresser and can grind reamers and drills with shank and cutting diameters from less than 0.013 ” to 0.375 ” and helical flute angles from 0° to 60°.

Norton’s grinding wheels allow the company to precisely control the flute radius, according to Marion. The T2 system is a high-strength glass bond in grit sizes from 120 to 600, while Michigan Drill applies 1,000-grit Univel-bond CBN wheels to impart fine finishes. The T2 CBN wheels, when cooled with oil, can grind up to 5,000 drills between dressings.