Frequently Asked Questions

How long has Cowan been in business?

Cowan Precision Grinding was started by Frank Cowan in 1968 in Burbank, California, and has been in continuous operation ever since. 2019 is our 51st year of precision grinding excellence!

Where are you located?

Cowan Precision Grinding is located in Sylmar, California, approximately 20 miles northeast of downtown Los Angeles. Our address is: 12864 Foothill Boulevard, Sylmar, California 91342.

Is Cowan ITAR Compliant?

Yes. Cowan Precision Grinding is in compliance with the requirements of the International Traffic in Arms Regulations 2011 (ITAR) as published by the U.S. Department of State, Directorate of Defense Trade Controls.

Can I download your Supplier Quality Clauses document?

Yes. Download our Supplier Quality Clauses document.

Can Cowan grind inside diameters well as outside diameters?

Yes. Cowan is expert at I.D. grinding. We have advanced precision CNC grinders that can hold extremely close tolerances – fifty millionths of an inch – on diameters from .375” to 12.0”, and up to 8.0” deep. 

Does Cowan grind hard-chrome plated surfaces?

Yes. We have ground many thousands of hard-chrome plated parts for a variety of industries and applications. We work closely with local, NADCAP approved hard chrome plating suppliers to expedite your job and guarantee top quality. Our hard-chrome grinding process is compliant with BAC 5032. 

What grinding services does Cowan offer?

Cowan Precision Grinding offers: I.D. and O.D. grinding; internal and external taper grinding; O.D. profile grinding; diamond-roll form grinding; and hard-chrome grinding per BAC 5032. 

What are your size capacities?

We can grind outside diameters up to 12.0” x 42.0” long; and inside diameters form .375” x 12.0” and up to 8.0” deep. 

Can Cowan handle outside processing?

Yes. Cowan Precision Grinding works with qualified local processors to expedite your grinding job. Our services include: hard-chrome plating, magnetic inspection, penetrant inspection, surface grinding, lapping and deburring.

For hard-chrome plating and magnetic inspection, we use only NADCAP approved sources. 

Does Cowan grind close-tolerance, complex parts?

Yes. Cowan specializes in close-tolerance, difficult parts. We grind a variety of materials, including 304 stainless steel, Inconel and titanium, and we are experts at close tolerance work. We can hold diameters and roundness within ±.00005” (fifty millionths of an inch), and we have the knowledge and equipment to grind thin-wall parts and very complex configurations. 

Does Cowan offer planning and consulting services?

Yes. In the last forty years we have gained a wealth of hands-on precision grinding experience, and our customer have come to rely on our knowledge and expertise. We offer free advice and information about grinding on everything from stock removal to heat treat distortion, and we can save you time and money when it comes to preparing your parts. And, best of all, our advise is free.

The next time you have questions about a job that requires precision grinding, give Phil Cowan a call at (818) 361-3512 or email him at Use our experience to get the job done right. 

Who do I contact to find out about doing business with Cowan Precision Grinding?

We welcome your inquiries. Please contact us today at 818.361.3512 or email us to find out what more than fifty years of precision machining knowledge and experience can do for you. 

“2019 is our 51st Year of Precision Grinding Excellence!”