-- The Home Page of the Finishing Industry
A website for Serious Education, promoting Aloha,
& the most FUN smiley you can have in metal finishing.
    no popups, no spam
on this site
current topics
topic 3383

Hardness of hexavalent chrome


Can anyone tell me where to find values for the hardness of electroplated hexavalent chrome? I need values according to the Vickers, Knoop, and Rockwell C scales.

Tammy Utzler
- Johnstown, Pennsylvania


The hardness for the electroplated hexavalent chromium is between 450 Hv and 1200 Hv --depends on the conditions of your process (current density, temperature, concentrations and bath contamination).

JosÈ Francisco Costa
- Riome»Portugal


Hi Tammy,

I do believe Jose's range to be a little wide open. We have numerous chrome tanks with conventional sulfate catalyst, mixed sulfate/fluoride catalyst and proprietary non-etch catalyst. The hardness is checked monthly on all types and is always in the 900-1100 Hv range. While it may be possible to plate as low as 450 Hv I believe you would have to be operating way outside recommended parameters. Converting one hardness number to a different scale is not a recommended practice as each hardness test was developed for specific applications. But if you must, ASTM E 140 has conversion tables. Also anything you can find on hardness by Jack Horner or Sur-Fin proceedings will give more in depth information

Rick Richardson, MSF
Dayton, Ohio

This public forum has 60,000 threads. If you have a question in mind which seems off topic to this thread, you might prefer to Search the Site

ADD a Comment to THIS thread START a NEW threadView CURRENT TOPICS

Disclaimer: It's not possible to diagnose a finishing problem or the hazards of an operation via these pages. All information presented is for general reference and does not represent a professional opinion nor the policy of an author's employer. The internet is largely anonymous & unvetted; some names may be fictitious and some recommendations may be deliberately harmful.

  If you need a product/service, please check these Directories:

JobshopsCapital Equip. & Install'nChemicals & Consumables Consult'g, Train'g, SoftwareEnvironmental ComplianceTesting Svcs. & Devices

©1995-2018, Inc., Pine Beach, NJ   -   About   -  Privacy Policy
How Google uses data when you visit this site.