General Broach and NuSol Combine Efforts to Improve Grinding Process

General Broach of Morenci, MI, and Chemtool Incorporated, headquartered in Crystal Lake, IL, recently combined their efforts to improve the grinding process at General Broach. "Both companies were started in the early 1960s and have diversified their product lines over the years," said a company spokesperson. "Each company was designated as the first in their industry to become a Ford Q-1 supplier, and both were one of the first in their respective industries to become ISO 9000 certified."

Five years ago, 90% of General Broach Company's business was automotive related. General Broach supplied broaches to cut the internal, external and blind splines for gears that go into automotive power-train parts. Because of the climate in the automotive industry, they knew they had to diversify. Today General Broach has refocused their production emphasis to aerospace customers and other OEM manufacturers of 'off road' equipment, agricultural equipment, firearms and hand tools. They manufacture broaches from 0.300 to 8.5 inches in diameter and up to 96 inches in length to meet their customer demands.

Chemtool Incorporated also had a number of automotive customers. They also faced a similar shift in business strategy. In response to the oncoming trend, Chemtool developed the NuSol line of cutting and grinding fluids. NuSol is a patent pending technology that was developed without the use of a traditional emulsification package that is used in oil containing products. NuSol also incorporates a heavier, more viscous base oil to improve tool life, corrosion control and boundary lubrication. In typical metalworking fluids, the emulsifier package is what breaks down in the fluid over time and that leads to rancidity, mist, heavy residues, coolant splitting, corrosion and the loss of tool life.

General Broach grinds three different types of steel alloy material, M4, M2 and T-15. Once material was delivered, the lathe department trims them to a desired diameter. The bars are then hardened in a salt heat treat operation reaching 2,100¡ F. The treating process can take up to three weeks. The bars temperature needs to be brought up slowly so that both the inner and outer cores of the broach bar reach a hardness of 64-66 Rockwell C. After the bars are hardened, they are ground with vitrified CBN wheels taking off as much as 0.100 per pass.

They had coolant-splitting problems (because of the plants hard water the emulsion would fall apart) with the three water-soluble coolants they used prior to installing NuSol. The splitting problems translated into stress cracking and burn marks on the broach bars they were grinding. The percent of finished broach bars with stress cracks and burns were small. However, because of these problems, General Broach had to slow their grinding process (grinding at a slower speed and also reducing the amount of stock that was removed on each pass) to insure the integrity of the part.

Extra measures by the machine operator also had to be taken to ensure the concentration of coolant remained at the proper level to maintain a tight emulsion with the old coolants.

The coolants prior to NuSol also left a slimy substance on top of their sumps as the emulsion weakened and clogged their paper filter, causing rapid indexing of the filter paper. They had to constantly add coolant to keep the concentrate up and the emulsion as tight as possible.

Because of the splitting and the problems associated with it such as rancidity, corrosion and poor broach bar finishes, General Broach was excited to evaluate NuSol. They prefer to use coolants that contain mineral oil because of the increase in lubricity for their part finishes and for increased depth of grind. Mineral oil also increases speed and feed rates over synthetic coolant technology.

Once NuSol was installed and operating, Larry Stover, General Broach production manager and machine operator Paul Bieber found the following benefits of NuSol.

The introduction of NuSol into the General Broach system led to an increase of 20% to production. We are no longer concerned about the burning or stress cracks of the broach bars we manufacture. We felt more comfortable increasing our feed rate, which translated into an additional 15% more production.
We have been able to grind off more stock on each pass. Additionally, Larry felt the surface finish was superior to anything they experienced prior to NuSol.
An added benefit is that NuSol runs cleaner and does not go rancid as previous coolants.
NuSol is also less expensive to run at General Broach because operators are not continually adding coolant into their system. We have reduced coolant consumption by 30 percent because we do not dump their sumps as often and we use less make-up coolant concentrate on a daily basis.

"Both companies have continued to grow year after year because of their innovation and constant drive for improvement and remain leaders in their respective industries," said the spokesperson.

For more information contact:

Larry Stover

Jack Raney

General Broach

307 Salisbury St.

Morenci, MI 49256

800-889-7555 / 517-458-7555

Fax: 517-458-6821

www.generalbroach.com

Dan Maguire

Chemtool Inc.

8200 Ridgefield Rd.

Crystal Lake, IL 60039

262-723-6590

dmaguire@chemtool.com