Heat number

An example of a heat number on a plate.

A Heat number is a identification number that is stamped on a material plate after it is removed from the ladle and rolled at a steel mill.

Industry quality standards require materials to be tested at the manufacturer and the results of these tests be submitted through a report, also called a Mill Sheet or Mill Certificate. The only way to trace a steel plate back to its Mill Sheet is the Heat Number.

Numerical Significance

Usually, but not universally, the numbers indicate:

• the first digit corresponds to the furnace number
• the second digit indicates the year in which the heat was melted
• the last three (and sometimes four) indicate the melt number.

References

• Definition at about.com