Just like individuals, each business will have its unique challenges and some commonalities as well. For heat treaters, the need to maintain customer approvals, industry accreditations, equipment calibration and furnace efficiency are vital to their current and future ability to provide heat-treatment services. Yet these are not easy to achieve in optimal conditions, and today’s world is indisputably suboptimal.

For heat treaters working in medical-device manufacturing, the need is arguably greater than in other noncritical industries. Lives depend on the quality of the parts that are produced. To prevent output deficiencies, critical processes such as heat treating must be validated during manufacturing to prove that they are fit for purpose, satisfy regulatory requirements and reduce overall risk.

One way to demonstrate continued focus on heat-treatment process quality is through the MedAccred program. MedAccred is an industry-managed, consensus-driven approach to ensuring critical manufacturing process quality throughout the medical-device supply chain. With a goal of reducing risk to patient safety, MedAccred addresses industry challenges such as number of recalls, flow down to sub-tier suppliers and purchasing controls through a shared, industry-wide approach. Subscribers include Johnson & Johnson, Medtronic, Philips, Stryker, Boston Scientific, Baxter, Roche Diagnostics, Bausch Health and BD.

The MedAccred Heat Treatment Task Group, led by Bruce Dall of Stryker, evaluates the performance of heat treaters in the medical-device industry against predetermined audit criteria. Auditees are given insight into their opportunities for improvement through nonconformance identification, and those who perform at the highest level are granted MedAccred accreditation.


AMS 2750 is the key pyrometry standard referenced by the aerospace industry in the Nadcap audit criteria. This specification covers pyrometric requirements for thermal-processing equipment used for heat treatment. This includes temperature sensors, instrumentation, thermal-processing equipment, system-accuracy tests and temperature uniformity surveys. These are necessary to ensure that parts or raw materials are heat treated in accordance with the applicable specification(s). Initially issued in 1980, revision E was issued in 2012. After a thorough review, the FDA has granted complete recognition of AMS 2750 for use in the heat treatment of medical devices.


Dall, who is the senior staff quality engineer – metal injection molding – at Stryker, said, “In most other environments we are competing organizations, but when we come together as a MedAccred Task Group, we are able to put aside our rivalries in the interest of quality and working toward consistently safer products for our patients.

“Ultimately, the goal is to achieve a consistently high level of product quality from our special-process vendors. The fact that we are seeing suppliers stepping forward to proactively gain a MedAccred heat-treating accreditation is a strong indication of how important this program will be to the future of the industry, and I am proud to be at the forefront of this effort.”

If your organization, like so many at this time, is trying to balance many competing demands, the following tips compiled by the MedAccred team may be helpful.


Maintain Your Self-Audit Activity

Even if it is limited to a desktop review at this point, ensuring a continued focus on your procedures and records means that they remain front of mind and may help to avoid silly mistakes once normal operations resume. This could be an opportunity for heat treaters to ensure that the following records are current:

  • List of equipment
  • List of purchased services
  • List of quality personnel and approved heat-treating personnel on each shift
  • List of customers and specifications
  • List of heat-treat specifications that you work to
  • Copy of internal general procedures for heat-treat processing, pyrometry and testing/inspection of heat-treated product
  • Organization chart
  • Personnel training


Communicate Openly and Often

Your customers, registrar, regulator, suppliers and other stakeholders want to know how you are doing. The performance of your business affects more than your business. We are all experiencing many of the same challenges, so you may be able to obtain extensions, waivers, etc. to cover you for this period.


Case Study

Vac-Met Inc. gained MedAccred heat-treating accreditation in July 2018. This was a very proud achievement for our team. The MedAccred audit is not a simple checkbox exercise. The auditor drills down deep into the procedures and records, as well as observes parts-processing in real-time. We were delighted to be awarded ongoing accreditation following our first reaccreditation audit last year as proof of our continued focus on compliance to customer requirements and industry standards, such as AMS 2750.

We had been involved with the Nadcap program since 2003. While we undoubtedly benefited from the similarities between the programs, the medical-device industry, like the aerospace industry, has its particular requirements. An example is the need for process validation as part of the MedAccred program. This is not part of the Nadcap audit.

The COVID-19 pandemic put our next MedAccred reaccreditation audit in jeopardy. Through no fault of our own – or anyone else’s – we were at risk of having our accreditation lapse. Measures such as travel restrictions and social distancing, as well as concern for the safety and welfare of all involved in the audit, were making it increasingly difficult to conduct an on-site audit.

We were adamant we wanted to maintain the coveted MedAccred accreditation we had worked so hard for. So we have worked with the MedAccred team and, at the time of writing, are looking forward to being the first to pilot the MedAccred virtual-accreditation extension audit. This will give the MedAccred auditor the opportunity to conduct our audit at a distance, covering the key requirements and permitting Vac-Met Inc. a three-month extension on our accreditation. Is it ideal? No. But hopefully it will allow us to demonstrate that, even in challenging times, our dedication to quality and ability to satisfy our customers’ requirements holds true, and this will provision us until the dark times have passed and we can welcome the MedAccred auditor back on-site again.

- Wayne Terwilliger, plant manager, Vac-Met Inc.



Adapt Where Possible

When “business as usual” is just not an option, work with your customers and regulators to identify what adaptations you can make that enable you to continue to provide the service they need at the level they expect. While you maintain control of any activity granted a temporary deviation from a requirement, avoiding the disaster of not returning to compliance once this situation has passed will be critical for ongoing conformity.

MedAccred subscribers recently authorized virtual accreditation extension audits to enable companies whose accreditations were due to lapse a safe way to maintain their status. While not as desirable as an on-site audit, it is bridging the gap for now.


Update your Process Controls

You must be able to demonstrate that you have reviewed the process-control requirements for each of your customers and that you have an internal procedure and “system” that documents compliance, including to other testing and controls required by specifications. Make sure that you have updated your internal documents to reflect any contingencies you have in place for the current situation. Some of the process controls to think about include:

  • Pyrometric testing
  • Lot-based or periodic tensile testing
  • Periodic metallurgical testing (e.g., IGO/IGA testing, eutectic melting, cladding diffusion, high-temperature oxidation, etc.)
  • Decarburization/surface-contamination testing
  • Leakup-rate testing
  • Hydrogen pickup testing
  • First-lot forging qualification testing
  • Carburizing and AC7101/4: Gas and/or ion/plasma
  • Metallography/microhardness
  • Surface contamination of steels (IGA/IGO, decarburization)
  • Titanium testing (Alpha case and hydrogen pickup)


Learn Lessons from Available Data

The MedAccred Heat Treating Task Group has published an audit handbook and a pyrometry guide, which are well worth a read. In addition, the Nadcap program publishes an overview of some common nonconformances that arise in heat-treatment audits. Any heat treater looking for opportunities to ensure the robustness of their operation should consider the following:

  • Conduct thorough, regular self-audits covering all aspects of your heat treatment, follow up on any concerns with root-cause analysis (Five whys or Ishikawa are great tools for this) and implement sustainable corrective actions. Validate that the corrective actions are actually sustainable at a later date.
  • In ordinary circumstances, do not limit your self-audit activity to paperwork. Spend time on the shop floor observing the operators at work.
  • Make sure your internal procedure specifies the method for determining heat-up rate, start of soaking time, end of soaking time and cooling rate. Omitting these details is a common nonconformance in Nadcap audits.
  • Keep the calibration of your equipment and associated records up to date. This includes things like vacuum instruments, flowmeters, dew-point meter(s) and the related master gauges.
  • Check that instrument calibration records and stickers and the calibration of primary, secondary standard and field test instruments show conformance to the requirements of AMS 2750 or more stringent customer requirements.
  • Verify that there is a system in place to review pyrometry procedures and the results of tests (whether performed in-house or by an outside source) to ensure that AMS 2750 or more stringent customer requirements are being met.
  • Ensure that the internal TUS procedure conforms to the requirements of AMS 2750 or more stringent customer requirements. Also ensure that temperatures indicated by all furnace thermocouples are recorded and included as part of the TUS record and that the thermocouple correction factors are stated unambiguously and used correctly.
  • Validate that the internal SAT procedure conforms to the requirements of AMS 2750 or more stringent customer requirements. Also validate that the SATs are performed on the temperature control and recording systems as required by the applicable instrumentation type, as well as any additional recording systems used for product acceptance in each control zone of each piece of thermal-processing equipment.

For more information: Contact Connie Conboy, director, MedAccred Program, Performance Review Institute (PRI) at MedAccred@p-r-i.org.