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Ted Mooney, P.E. RET
Pine Beach, NJ
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for Metal Finishing since 1989
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Hard Chrome Thickness and Hardness Measurement Equipment
Q. We currently are operating a chrome plating facility where we do both ID and OD plating (mostly ID). We are interested in knowing if there is measuring equipment that is available to measure our coating thickness while the product being plated is still submersed in the acid tanks. The ID of our tubing that we plate range from 1-1/4" to 5-1/2" and in lengths from 8' to 40' with the average being around 24'. We are plating hard chrome on steel, stainless steel, and brass tubing. Our plating thickness usually ranges between 0.007" to .01" Any suggestions anyone may have would be greatly appreciated.
Brian Mercer- Red Deer, Alberta, Canada
2002
A. MR.BRIAN I READ YOUR QUESTION TO MEASURE THE CHROME THICKNESS, YOU CAN MEASURE THE CHROME THICKNESS BY USING "KOCOUR 6000 ELECTRONIC THICKNESS TESTER.
Popatbhai B. Patel
electroplating consultant - Roseville, Michigan
Ed. note -- Readers: please try to discuss the technology of different measuring approaches rather than brands & sources (why?)
Multiple threads merged: please forgive chronology errors :-)
Need to measure hard chrome plating thickness on stainless
Q. We are a manufacturer of Coal Prep Dryers, using industrial chrome to improve the service life of our components. I need a non-destructive method to measure the depth of industrial hard chrome on 304 stainless. I have been informed that here is no way to do this. Magnetic and eddy current methods will not work, but surely someone has developed a cost effective way to do this. Any advice would be welcomed.
Thanks......
Jeremy AllenCoal Dryer Manufacturer - Raleigh, Illinois, U.S.
2004
A. X Ray fluorescence will do the job.
Jeffrey Holmes, CEF
Spartanburg, South Carolina
2005
A. Hi
XRF probably won't work. Stainless is 10+% Chromium. The thickness measurement will be off because of this, maybe not by much, but it will affect the measurement. You could probably use FIB (focused ion beam) and SEM (scanning electron microscope), but your part would have to be cross-sectioned for that.
Jeff Marten- Colorado Springs, Colorado, USA
A. All that needs to be done is to calibrate using chrome on stainless standards.
Jeffrey Holmes, CEF
Spartanburg, South Carolina
A. Jeff, industrial hard chromium plating is about 2 mils, or 50 microns, thick. I was under the impression that such would be too thick to get an x-ray fluorescence beam through: is that not the case?
Lee Gearhart
metallurgist - E. Aurora, New York
A. Lee: Where does it say that hard chrome is .002" think? We plate hard chrome anywhere from .0001" to .060" I don't know what the absolute limit for XRF is, but it will certainly measure coatings .002"+.
Jeffrey Holmes, CEF
Spartanburg, South Carolina
A. I have an older EDXRF (Fischerscope 1510) and the limit for Chrome is 360u", or 0.36 mils. Maybe a WDXRF would work? I don't know a whole lot about WDXRF machines, but don't they use a flat vacuum-assist sample tray? If so would the sample need to be flat?
Jeff Marten- Colorado Springs, Colorado, USA
Multiple threads merged: please forgive chronology errors :-)
Q. I need to know about equipment to certify the thickness of hard chrome & the hardness already applied on mold's face.
Please if you don't understand my question, I will really appreciate your comments and answer,
Thanks.
hard chrome supply - Olmito., Texas
September 27, 2008
A. Esteban,
You do need to give us a little more information such as:
What materials are you plating (Aluminum, mild steel, stainless steel)?
What are the thicknesses required?
Do you have to plate to finish sizes?
With this sort of information we can better advise on what would be the best technique for thickness determination, whether it be a dimensional check or maybe by magnetic/eddy current etc.
Aerospace - Yeovil, Somerset, UK
A. There are indirect non-destructive methods to obtain approximate hard chrome thickness. When substrate is magnetic, a very sensitive and calibrated magnetic device "feels" how far beneath the chrome is the substrate. This is translated to chrome thickness. If the substrate is non-magnetic an X-ray equipment would be a good option though expensive and dangerous.
Hardness will be more difficult to measure because readings are more influenced by the substrate hardness as the coating becomes thinner. Crazy as it may sound, accurate values can only be determined by microscopic examination on a cross section (direct measurement and Knoop or Vickers indentation). Yes, you would have to cut a piece from the mold in an area that received chrome. This may be impossible or too risky, your customer may kill you. So, it is generally acceptable to plate a coupon made of the same alloy together with the mold.
Monterrey, NL, Mexico
Q. Sirs,
We are manufacturing brake linings in India. We do hard chrome plating for our moulds.The coating thick is 20~25 microns.I would like to know what is the method of checking hardness of the coating.
Mould maker - Chennai, India
October 8, 2009
Q. We want to measure hard chrome plating on SS 316 about an average range of less than 100 microns.
Which machine will workout best for this application and we tried with Elcometer and Fischer but nothing works.
- Chennai, Tamilnadu, India
Ed. note -- Readers: please try to discuss the technology of different measuring approaches rather than brands & sources (why?)
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Ed. note: Readers may also be interested in these closely related threads:
Topic 0873, "Hard chrome plating thickness measurement"
Topic 25628, "Best way to measure chrome plating hardness"
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