Dirty Hardware Abatement | Elimination of Cadmium and Hexavalent Chromium in Ground Vehicle Systems

By Matthew Withun, PEO Ground Combat Systems

The U.S. Army and other DOD agencies still use hexavalent chromium and cadmium-plated mechanical parts, electrical components, and fasteners on many of its programs. These substances are carcinogenic and hazardous to the environments in which they are produced or disposed of, and they are a human health hazard. This clean hardware abatement initiative is working toward the elimination of thousands of parts plated with hazardous materials currently procured by the Army for ground vehicle systems. This initiative will enable our acquisition and sustainment processes to utilize clean hardware for current and future vehicles.

So why is the Army still using known carcinogenic materials to plate components in their ground vehicle systems? This is a simple question with a not-so-simple answer, as there were three primary challenges that could undermine the execution of an enduring abatement initiative.

First, there is a lack of an applicable military-grade performance specification that meets OEM requirements.

Next, the fastener industrial base did not return requests for quotes given the low demand (a single program to start) that would be generated during the lengthy implementation process.

Finally, the volume of changes required to supporting documentation and drawings as a part of the engineering change process (ECP) would drive high cost and complexity into the initiative.

None of these issues were insurmountable, but the combination of issues had been a deterrent to undertaking this significant initiative—until now.

In late 2019, the Program Executive Office for Ground Combat Systems (GCS) and DEVCOM Ground Vehicle Systems Center (GVSC) proposed an ambitious initiative to address this lingering issue. With the Assistant PEO Logistics (APEO Log) Office as the initiative lead, the team used the CTMA Program to bring together several key contractors for the abatement initiative including:

  • BAE – Platform OEM developer for several key systems requiring abatement
  • Booz Allen Hamilton – An innovative resource providing data analytics and ML processes to reduce the burden of logistic products (National Maintenance Work Requirements, technical manuals, etc.) and drawing updates
  • MNP Fasteners – One of the largest automotive fastener suppliers in the U.S. and a major military fastener supplier

“Transitioning from cadmium/hexavalent chromium to zinc-nickel is significant and necessary to ensure that we are protecting our Service members, civilian, and contract personnel, while reducing the environmental impacts attributed to prohibited materials,” says Michelle Link, Director of Logistics at PEO GCS.

In addition to the core team, the initiative needed a sponsor as well as a pilot platform for our initial abatement initiative. PM Self-Propelled Howitzers Systems (SPHS) offered to fund the effort for the Paladin (M109A7) platform as the pilot for our abatement initiative. A modern platform such as the Paladin will potentially have thousands of components with hazardous plating, including fasteners, electrical connectors, hydraulics components, and miscellaneous interior and exterior hardware. In fact, our initial analysis of the Paladin identified over 3,000 unique fasteners and about 900 of those were flagged for abatement using our analytics tools.

Of primary concern was that the DLA had no means to identify the zinc-nickel plating when issuing Requests for Quotation (RFQs) to the fastener industrial base. There were several existing industry performance specifications, but most were specific to automotive manufacturers and not necessarily compatible with the Army’s requirements. To solve this issue, our team authored and published the MIL-PRF-32647 Performance Specification for Zinc-Nickel Electroplating for Fasteners. The performance specification details the military’s performance requirements for our zinc-nickel plated fasteners and includes two torque-modifiers (TMs) that have been proven to allow for “drop-in” replacements of cadmium and hexavalent chromium fasteners. This eliminates the need to revise the torque drawing and other requirements including National Maintenance Work Requirements (NMWRs), Depot Maintenance Work Requirements (DMWRs), and technical manuals.

Zinc-nickel alloy coatings (usually composed of approximately 85 percent zinc and 15 percent nickel) are electroplated on carbon steel. These coatings offer superior corrosion protection, excellent wear resistance for mechanical parts, and perform very well in high-temperature environments. Moreover, the automotive industrial base has invested a significant amount of time and money developing zinc-nickel solutions over the past three decades, and we now stand to benefit from those investments. Validation will be conducted on the new fasteners, parts, and subsystems as deemed necessary, including any safety-critical elements.

“We are confident that the specified zinc-nickel system achieves the goals of enhanced corrosion protection while eliminating the use of identified carcinogenic substances. The coating composition was selected to minimize hydrogen embrittlement risks during electroplating. In addition, we added the unique requirements for plating friction behavior that are important for clamp load critical fastening applications. That was a key element in the development of the plating requirements,” says John Fragnoli, Engineering Services Director at MNP Fasteners.

We next anticipated that when the DLA attempted to purchase zinc-nickel plated hardware, the industrial base would be reluctant to participate due to the expected low initial volumes. There was also a related concern that the conversion costs from cadmium and hexavalent chromium would result in a prohibitive increase to the component unit price. Our teammates from MNP Fasteners were tasked with addressing this concern by engaging the industrial base to develop a list of qualified distributors, manufacturers, and platers that would sell zinc- nickel-plated hardware to the Army in support of this initiative. The team would also work with the sources of supply in the DLA industrial base to keep any incremental costs associated with zinc-nickel from presenting an obstacle to initiative execution. Initial estimates show that the cost of zinc-nickel is comparable to that of cadmium and hexavalent chromium-plated parts when volumes are comparable. Achieving that comparable volume, however, will take time within the initiative.

In the meantime, we are developing and employing the use of ML. This innovation will be used to analyze drawings, technical manuals, and logistics and maintenance documentation, and then redline and update affected documents automatically. This capability, called the Automated Redlining Tool, has the ability to significantly reduce the workload required to update these documents during the ECP as well as improve the quality of the ECP execution. These tools can search the target document text (and graphics) find and replace part numbers, specifications, National Stock Numbers (NSNs), or any text that needs to be modified. Booz Allen Hamilton brings this innovative capability to our team and is also developing similar capabilities in support of other DOD clients.

“Abatement of hexavalent chromium and cadmium on a system is not an impossible task. It just requires a great deal of planning and preparation. Efficiencies in this process are key,” says Lisa Graf, Chief Sustainment Engineer for the APEO. Ms. Graf goes on to say, “the creation and use of the Master Fastener Database for PEO GCS, and the Redlining Tool, are examples that we can use that save us months, if not years, in planning and millions of dollars for updates to the Tech Manuals and drawings. With modern processes and tools, we can do this much more quickly than in the past.”

In addition to the above effort, several Army depots use hard chrome plating operations to refurbish worn steel components such as gears and shafts. This was originally done due to it being the difficulty of securing new components. Decommissioning those chrome-plating facilities would be a significant step in the elimination of hazardous materials for both operations personnel and the environment. Our initiative is working toward shutting down these operations by simply working with the OEMs to buy new parts.

Looking forward, our team is developing similar initiatives in support of the other PEO GCS platforms such as Bradley, AMPV, M88 Recovery Vehicle, Extended Range Cannon Artillery (ERCA), and Field Artillery Ammunition Supply Vehicle (FAASV). As each of these platforms executes its abatement efforts, the amount of cadmium and hexavalent chromium-plated hardware that the Army purchases over time will gradually diminish as the demand for clean zinc-nickel alternatives overtakes the market.

What does the future look like? OEM production facilities will be building vehicles using clean hardware, depots and sustainment activities will be purchasing zinc-nickel hardware, DOD sustainment facilities will no longer need to use specialized processes to work with these hazardous materials, and personnel will no longer be concerned with the negative health hazards. This future state may take some time, but the momentum this abatement initiative has generated is building to ensure the elimination of cadmium and hexavalent chromium on Army platforms is all but certain.


Additional contributors to this article are Christina Burrows and Tom Sanders from PEO GCS. For more information on this initiative, please contact Lisa Graf at Lisa.J.Graf2.civ@mail.mil or Matthew Withun at Matthew.C.Withun.ctr@mail.mil, in the APEO office at PEO GCS.