Posted by: Mark Anderson
on October 3, 2023 | 3 min. read
on October 3, 2023 | 3 min. read
Metal manufacturing is a complex process. Raw materials go on quite a journey—from the mill all the way to the end user. During this production process, the metal changes hands multiple times before fully transforming into a finished product. With so many steps and parties involved, how can you ensure the metal's quality stays consistent every step of the way? The answer lies in heat numbers.
What are Heat Lots?
Heat numbers, also known as heat lots, are identification codes stamped on metal plates. They play an important role in verifying consistent metal quality from start to finish. These numbers show that each batch meets the manufacturer’s standards and required specifications for that specific metal. Essentially, heat numbers enable producers to trace each production run, facilitating proper quality control checks at every stage of the process.
Why are Heat Lots Important?
Heat numbers are crucial in certifying the quality of metal coils arriving at service centers. When a massive coil gets delivered straight from the mill, its heat number validates that the metal meets standards.
Each coil also comes with a Mill Test Report containing key background details, including the origin of the raw source material and the coil’s specific chemical and physical properties. This information is crucial for both quality control and compliance reasons.
Some overseas mills, unfortunately, don’t fully disclose a metal’s true mining source or composition. But for ensuring quality control and compliance, those specifics must be documented. Heat numbers help ensure that vital data gets reported accurately.
What Are Material Test Reports (MTRs) vs. Mill Test Reports (MTRs)?
Material Test Reports (MTRs) act like a metal’s rap sheet. They document that the received metal fits all the correct specifications, including data on mechanical properties, chemical makeup, and more.
Mill Test Reports (MTRs) also certify that the metal meets specifications, but they specifically come from the mill that produced the metal. Mill test reports include details like the metal’s chemical composition and physical properties based on testing conducted at the mill.
Both types of reports come directly from whoever performed the testing, whether that is a third-party testing facility or the mill itself. The transparency provided by Material Test Reports and Mill Test Reports helps ensure quality and compliance across the metal supply chain.
How to Meet Metal Compliance Standards with Heat Numbers
With the transparent information from Mill Test Reports, heat numbers become a valuable compliance tool. The paperwork trail helps verify that only quality metal from reputable mills enters each supply chain step.
This provides necessary checks and balances for today's complex, global metal industry. Heat numbers enable manufacturers to maintain consistent quality and meet compliance standards across borders.
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