Chromium Plating for Engineering Applications (Hard Chrome)

Recommended Time & Experience: Some experience or training in the art and science of functional chrome plating is recommended.  For those a few years away from taking any chemistry courses, the Chemistry Refresher course offered by NASF Foundation is highly recommended, but not required as a pre-requisite.   

Description:  This course provides an in-depth understanding of the applications, properties, and safety requirements when using functional chrome.  It explains why functional chrome would be used and how it would be applied to a substrate.   

Core Elective: Master Surface Finishers (MSF) designation.   

Designed For: But not limited to: Operators with ‎some level of chrome plating experience including but not limited to plating line work, ‎supervisors,‎ sales personnel serving metal finishers and managers.‎ ‎ 

Course Content Level:  Intermediate to Advanced (200 to 300 Level) 

Approx Hours to Complete:  10 Hours‎ 

Learning Objectives:  Those completing this course and/or earning a certificate in Chromium Plating are able to: 

  • Demonstrate an understanding of the application and properties of functional chrome as well as the safe handling, storage, and uses for this chemistry.   
  • Recognize the proper functions of equipment, waste-treatment handling, regulatory requirements, and the role of catalysts and additives in hard-chrome applications.   
  • Articulate the importance of pre-treatment preparation including masking, blasting, and monitoring and control of the most common chemical methods.  

Course Options

  • Home-Study

    Member: $900 | Non-member: $1,300

  • Optional Exam

    Member: $200| Non-member: $300

Course Description

1. Chemistry for Hard Chromium Platers
This lesson covers the basic chemistry principles needed to better understand the plating process. The lesson begins with the structure of an atom and builds upon that basic information to yield an understanding of chemical reactions as they may be employed to process parts for plating, the plating process itself, and post-plating processes as well.
2. Electricity for Hard Chromium Platers
This lesson discusses basic principles in electricity, beginning with Ohm’s Law. Basic rectification principles, how ammeters and voltmeters work, and how current is distributed over a part are important concepts delivered by this lesson. A special focus is given to the use of shields, robbers, bipolar anodes and auxiliary anodes as a means of more evenly distributing current.
3. Electrochemistry for Hard Chromium Platers
This lesson begins with Faraday’s Law and shows how it can be used to predict plating time. The lesson then goes on to the Electromotive Force Series, how the corrosion behavior of metals can be predicted, and how the EMF series can explain processes such as zincating of aluminum prior to chromium plating. The concepts of polarization in plating and factors affecting deposit structure are also covered.
4. Equipment for Hard Chromium Plating
This lesson provides information on the equipment used for hard chromium plating, including tanks, bus bars, racks, rectifiers, agitation systems, process heating/ cooling and anodes. A special focus is placed on anode condition and maintenance, along with proper ventilation practices and emission controls.
5. Masking Techniques
This lesson covers the various methods employed to selectively plate chromium. Masking methods such as stop-off lacquer, waxes, tapes, permanent masks, and high temperature melts and solvent-based commercial dip maskants are described and discussed, along with the advantages and disadvantages of each. A brief discussion on use of conforming anode-mask combinations and out-of-tank plating as a way to minimize masking is also provided.
6. Mechanical Surface Preparation
This lesson covers physical methods used to prepare a surface for plating, including wet and dry blasting, grinding, polishing, shot peening, and honing. A brief discussion on methods used to repair damaged surfaces prior to plating (dot welding, heavy nickel build-up) is also provided.
7. Chemical Surface Preparation
This lesson covers the chemical methods used to prepare a surface for plating, including the role of alkaline cleaners, zincating of aluminum, and reverse etching methods of various metallic substrates, such as copper, steel, tool steel, stainless steel, electroless nickel, parts that have been chromium plated, and cast iron.
8. Basic Chromium Plating Principles

This lesson discusses the three major types of hard chromium plating processes (conventional, fluoride and non-fluoride mixed catalyst baths).

Chemical make-up and operational conditions for each process are provided. The lesson also focuses on the mechanism of deposition of hard chromium and how various structures are obtained (thin-dense, for example). Another special focus is hydrogen embrittlement, its causes and cures.

9. Analysis & Control of Chromium Plating Solutions
This lesson will provide guidance on analytical procedures that are used to determine the concentration of the main ingredients and impurities in hard chromium plating solutions. It also shows how to calculate chemical additions to the process and how surface tension can be measured. Another focus is Hull Cell testing and hardness measurement.
10. Troubleshooting & Purification of Chromium Plating Solutions
This lesson describes the most common hard chromium plating defects, their potential causes and possible solutions.