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.
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.
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