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  • Writer's pictureSusanne Nordman

Valuing an Electromagnetic Chuck

Updated: May 6

In today’s turbulent economy with so many business acquisitions, closures, and mergers, used machinery auctions are certain to follow as manufacturers purge older equipment or set out to automate and renew their production floor. It has become common for us to be asked to put a value on used or pre-owned electromagnetic chucks or tables. While we are grateful to have our professional expertise valued enough to be asked to do this, there is not an easy answer to this inquiry.

To properly place a current market value on a pre-owned electromagnetic chuck, we caution you to remember that the more you know about the chuck, the better. When we value one internally, we collect as much history on the chuck as we possibly can before placing a price on it. Just knowing the size and top plate thickness are minimal factors and can be misleading if they are the only characteristics used in valuing it.

electromagnetic chuck
Pre-Owned Electromagnetic Chuck

Before we talk about all the attributes to consider when valuing electromagnetic chucks, let’s first establish their importance in the whole machining process. Who better to consult on this than the machinery manufacturers themselves.

Referencing a Mattison Machine Works rotary grinder manual we read, “The magnetic chuck is one of the most essential parts of a Rotary Grinder equipment. The character of work turned out from your Rotary Grinder depends to a very large extent upon the condition of the chuck. It must run true, it must be accurately flat and it must hold the work to the full limit of its magnetic power. For these reasons considerable detail is given regarding its construction, mounting and use.”

Straight from The Blanchard High-Powered Vertical Surface Grinder, No. 10 sales brochure we read, “Next to the spindle the chuck is probably the most vital part of a surface grinder.”

Keep in mind that Blanchard machines have Blanchard electromagnetic chucks on them because their chucks are unique to their machines only and are only made by them. So naturally they would speak highly of their own branded chucks. Mattison, however, was never a manufacturer of electromagnetic chucks. From approximately 1985 to 1997 electromagnetic chucks were manufactured in their facility under the Magna-Lock USA brand which was a division of MMW at that time. Consequently, their transparency about the value of the electromagnetic chuck is genuine and unbiased.

When reshoring took off in the United States in the 1970’s, it became evident that pricing of workholding made in the USA could not compare to many brands of workholding made in Asian countries. With price being valued more than quality craftsmanship, sourcing in the USA and the electromagnetic chuck market began to shift. With this being said, the manufacturer of an electromagnetic chuck and country of origin, due to availability of parts and service, are both big factors in determining its pre-owned value.

electromagnetic chuck on Mattison grinder

It is becoming more frequent to hear that business owners are scrapping their entire machine because the cost of replacement or remanufacture of electromagnetic workholding outweighs their perceived value of the machine. This affirms two things. One being that the pre-owned machinery market is not properly aligned with the supply and demand of the current market. The other would be that machinery is not properly maintained with good preventative maintenance including the electromagnetic chuck.

Many factors need to be considered to put a proper value on a pre-owned electromagnetic chuck. Here is a rough list of what we consider when valuing used electromagnetic chucks. Keep in mind this list would be good to review when making decisions on new electromagnetic chucks as well.

  • The original equipment manufacturer (OEM) of the chuck

  • The country of origin and if parts or service is needed, will that be challenging because of proximity?

  • Approximate date of manufacture, should be able to be determined by serial number

  • Size of the chuck

  • Top plate life on the chuck

  • If the chuck is still intact. If the chuck is opened, in pieces, parts missing, etc. the value would be greatly reduced.

  • Structural condition of the chuck.

  • Electrical ratings and characteristics and if they will work with your controller

  • Is the chuck water-tight?

  • Overall working condition including pertinent electrical readings

  • Top plate configuration, if its unique to a specific part or material, it may not be universal to hold most parts

  • Any special features, keeping in mind that some features could be detrimental to highly valuing the chuck

  • Parallelism and trueness

There may be other special characteristics to consider, and we would be happy to discuss your specific situation with you if desired. However, we cannot properly value a pre-owned electromagnetic chuck without having it in our facility for proper testing and evaluation. We also cannot do this service without charging for our time and any materials used.

As a supporter of remanufacturing, keeping pre-owned electromagnetic chucks in circulation within the industry is a way to reduce waste and costs while maintaining high levels of production, and we support that. As with all pre-owned products though putting an accurate and fair price on them is nearly impossible with a proper inspection and evaluation.


Obsidian Manufacturing Industries, Inc. is a Rockford, Ill. manufacturing company and is the OEM for Magna-Lock USA workholding, MagnaLift & Power-Grip lift magnets, and Arter Precision Grinding Machines as well providing surface grinding services. They are located at 5015 28th Ave. in Rockford, Ill. with a phone number of 815-962-8700. Check out more at


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