Friday, August 21, 2015

Heat Number

Heat Number is an identification coupon number that is stamped on a metal plate after it is removed from the ladle and rolled at a steel mill.

Industry standards requires materials to be tested at the manufacturer's and the result to be submitted through a report, also called the Mill Sheet/ Mill Certificate/ or Mill Test Certificate.

A Heat Number is a unique identification code that a technician stamps on a metal plate to provide information about it's origins. 
Heat Number is the only way to trace a metal plate back to it's Mill Sheet, and therefore is a very important part of quality assurance and control.

There may be three/ four or five segments in a Heat Number.

1) The first digit indicates which furnace is used to prepare the batch of molten metal. 

2) The next two digits tells about the year of casting.

3) The next two/ three digits describes the number of casting that year by the furnace. (Batch No.)

4) Heat number can have more segments to provide information about the manufacturer and their facilities. Like the facility number, if the manufacturer has more than one unit, or factories where the metal is casted.

5) It can also tell about the mold number which is used to make the product. This can be useful for matching replacement parts, as people can use the mold number to get an exact replacement.

This whole information corresponds to records that the manufacturer keeps for future references.

In quality control people subject a sample piece of metal from every batch to some testing to make sure it matches the quality standards and meets the required tolerances. 

They will be tested for contaminants, weak spots and other issues. If there is a problem with the metal, people can recall all other pieces of metal with the same Heat Number to check them and see if they share the issue.

The number also corresponds to records about the shift that handled the metal, what time of day it was cast and so forth. This information can be useful when people want to determine why the same quality control problems keeps recurring.

This can also be very useful for activities like Accident Forensics, where investigators may want to find more about a particular metal product to see if a problem with the metal contributed to the accident.

As long as the manufacturer keeps current records, it should be possible to trace and look up any piece of metal back to it's origins just by looking at it's Heat Number.