Applying NDT in Production

By Annabel Sebuc Sab-it

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I have been involved in production for the past 15 years, but I should say that I started in nondestructive testing (NDT). I hear coworkers say, “Oh her point of view changed since she is handling the full production and taking care of the metrics for the business.” Yes, that’s true. I’m taking care of the metrics and the business, but I’m taking care of the NDT, too. And that’s my first love before managing production.

What Is Nondestructive Testing?

NDT is the use of physical methods for testing materials and products without harm to those materials and products.

It is testing. Literally. It is inspection they say is a “nonvalue adding activity” in Learning to See but I disagree!

The Production Stage

Production refers to all the activities which are undertaken to produce goods and services for generation of income and satisfaction of wants. 

In the production stage, if there is a problem with the material used or the process implemented, it is best to have an immediate correction before a lot of products are produced that may eventually go to costly rework or scrappage. Failure of the product in the field will result in product recall, aircraft grounded, and loss of confidence of the customer. Catastrophic incidents due to poor quality products may result in airplane crashes, investigation, loss of lives, costly litigation, and closure of the company.

In a manufacturing environment, such as in aerospace, having machining working hand-in-hand with the NDT department is a great advantage. Giving on-time feedback on the inspection results will make a big impact.

How Can We Apply NDT in Production to Save Money?

First: As NDT experts, we can suggest an in-process inspection if there is a massive rejection due to cracks at the end of machining, for example if it’s from grinding. We can’t do anything if it’s not detected until the end of machining and final inspection. What we can do is to add a sampling inspection in between machining and final inspection to avoid massive rejection. For example, inspecting the first three pieces output from the machine after the setup. This will ensure that the setup is correct and will produce good parts.

Second: If a major rejection is suspected at the raw material level, as NDT experts, we can insert a random sampling inspection before machining begins. In this way, we can contain the bad batch or heat lot and it will not progress further at the machine shop. This will save labor and material costs that could have a big impact on the financial status of the business.

Third: Train staff to appreciate the importance of NDT.

Make people aware of the inspection. Have the machinists and engineers be knowledgeable about NDT. If they are aware, they can ask questions, such as, “If the parts that I produce undergo NDT, will they pass?” Machine operators can ask that question if they are aware that an inspection will be done on the parts. They will be conscious about changing the parameters of machining that can eventually impact the integrity of the part. Or engineers can ask “Will the parts be passed at inspection after I establish the operation sequence? Are the parameters I set enough for the parts to have no cracking during grinding?”

When you consider the impact of NDT on quality production, is it costly? Or can NDT save us money?

References

• ASNT, 2016, Materials and Processes for NDT Technology, American Society for Nondestructive Testing, Columbus, OH
• ASTM, 2022, ASTM E1444 Standard Practice for Magnetic Particle Testing for Aerospace, ASTM International, West Conshohocken, PA
• Quality Gurus Inc., “Value Added vs Non-Value Added Activities,” accessed 18 September 2023. https://www.qualitygurus.com/value-added-vs-non-value-added-activities/#:~:text=Inspection%20is%20a%20non%2Dvalue%2Dadded%20activity
• Rother, M. and J. Shook, 2009, Learning to See, Lean Enterprise Institute Inc., Boston, MA

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Annabel Sebuc Sab-it is the NDT Level III and Production Area Manager at MOOG, Baguio Philippines Facility. She is one of ASNT’s Faces of NDT in 2023.

Photo of raw material by Annabel Sebuc Sab-it.

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