What is a mill test report?
Unless you buy directly from a mill, you might not come into contact with a mill test certificate. They are documents all mills send to their customers along with their metal purchases, and each document verifies that the metal you're receiving meets the specifications of your order.
Mill test reports detail an important step in a metal product's journey: the step from the mill that melted the metal to the service center the mill sold the metal to. A mill test report is a quality assurance document that certifies a metal product's chemical and physical properties. Below, I'll outline what you typically see in a mill test report.
What's Included in Mill Test Reports?
While each mill typically has a different layout for their reports, the information on them is pretty universal. A mill test report will include the following:
The metal product's alloy, temper, thickness, width, and finish, along with ASTM and AMS (if required).
Heat Number or Heat Lots
The heat number is an identifying code to provide information about a metal product's origin. It provides the info for tracing material and verifies quality. This is also the only way to trace back to the original mill heat. This is sometimes referred to as a lot number.
Mechanical properties indicate the strength, ductility, hardness, and elasticity of steel products. These are important to ensure the material meets the physical needs of the end use of the product.
In the case of metal alloys, you'll also see a breakdown of the material's chemical properties. Depending on what alloy you're purchasing, the chemical makeup of the metal will need to fall within required ranges.
Any Additional Details Specific to Your Order
Specifications of your order will also be on mill test reports. For instance, you might see details related to AMS bend tests or the type of metal finish your product has. Basically, any extra information related to your order will be included.