We recently published a guest article written by Brad Pritts, one of the most experienced quality professionals I know, on the Sofeast Blog — that article is Can I trust Chinese steel products? It is a great case study.
Unfortunately, I can’t write anything similar about our clients’ projects because of strict NDAs, and there aren’t many good studies publicly available on the internet. So I’ll share some of his points from that post here and add some of my own comments…
Can material quality issues lead directly to product safety issues?
Brad works for Unibond, which produces brakes. In his company’s case, yes, there is a direct link between quality and product safety.
If a heavy-duty brake shoe is made of the wrong grade of steel and is mounted on a truck, it could result in disastrous consequences.
There are many other types of products where using the wrong type of steel leads to serious safety issues. Imagine if a skyscraper’s frame & pillars got built with substandard materials?
The buyer must know exactly what should go into the finished product
Remaining on the topic of steel alloys, they vary enormously in terms of physical properties.
Perhaps the biggest risk is using the wrong grade of steel, whether due to honest mistakes, fraud or anything in between. If the wrong grade is used, even the best quality in the world won’t make it right.
In the case of steel, the key questions are as follows:
- What is the chemical makeup? – How much iron, carbon, and a variety of alloying elements such as nickel, chromium, and manganese?
- What are the mechanical properties? – This is related to strength, hardness, and machinability
- What further processing is performed? – Once the steel is produced at the mill a variety of steps are performed to make it ready for use.
- What is the grade? – The steel grade communicates the chemical composition, properties, fabrication processes, heat treatments and forms of steel. Grading is very important as it gives a standard language for effectively noting the properties of steel.
Even our “simple” heavy-duty brake shoes use different grades of steel for their components and a dozen different grades for our brake hardware.
The buyer needs to have a plan for controlling what happens in the supply chain
Brad lays out an approach that makes a lot of sense:
Some of the measures quality-conscious importers use include:
- Specifying grades that provide an extra margin of safety
- Sourcing steel consistently with a limited number of qualified mills
- Performing incoming lab tests on each batch at the factories using the steel; monitoring the steel producers’ quality results
- Visiting the steel production facilities, and reviewing their quality practices
- Sending random samples for independent lab testing
- Testing parts in the event of customer complaints
We also monitor quality closely in those operations where the steel quality or grade can make a difference such as in welding or heat treatment.
How to confirm that the final product is fit for its purpose?
In addition to all the preventive measures outlined in the previous paragraph, buyers also routinely test their products. (This is not written in Brad’s case study, so I am adding to it in a way.)
First, of course, there are safety standards that need to be complied with. That’s a must. For example, see this video about some common toy lab tests.
Some companies try to go further, and it’s great. See how Tesla developed their own tests.
Second, the buyer should also conduct other types of tests on some finished products, as an extra assurance. If there is a doubt about a material’s grade, that can be checked (with chemical and/or physical testing).
Reliability and durability testing is quite important, too. (In a way reliability and safety totally overlap, of course.) See some standard drone testing here. If that drone is to be relied on to deliver critical medicine within a tight time frame, poor durability can lead to safety issues.
And third (it should come first, actually), proper verification and validation of product safety during new product development are extremely important. Most safety issues probably come from poor design.
Does this make sense to you? Are you checking material quality in the same ways outlined by Brad (in his case about steel)? Let me know by leaving a comment, please.