What’s a heat number?

Print anything with Printful



A heat number is a code printed on metal to track its origins and is important for quality control. It includes information on the furnace used, casting year, and casting number. The number can be used to trace materials, match replacement parts, and investigate accidents. Manufacturers can use it even if not required by law.

A casting number is a unique identification code that a technician prints on a piece of metal to provide information about its origins. Sheet metal and pipe are more likely to have this number, and in some cases, the law requires its use on metal products. The heat number provides a method for tracking materials and is an important part of quality assurance and quality control. People can usually find this near the edge or end of a finished piece of metal, and other information may be on the stamp as well.

There are three segments in a heat number. The first digit indicates which furnace a technician used to prepare a batch of molten metal. The following digits indicate the casting year and the last two or three digits describe the casting number. A number such as 222121 indicates that the metal came from furnace two in the year 2022, and it was the 121st smelting for that furnace that year. This information corresponds to a log that the manufacturer keeps for future reference.

In quality control, people put a metal sample from a given batch through some tests to make sure it meets required tolerances. People will test for contaminants, weaknesses, and other problems. If there is a problem with the metal, people can call up other pieces with that heat number to check them and see if they share the problem. The number also matches records on which shift handled the metal, what time of day it was cast, and so on. This information can be useful when people want to determine why the same quality control problem keeps recurring.

With the heat number, people can trace all the materials of a particular factory. Along with the casting number, the stamp includes a statement of the maker and facility, if the maker has more than one metalworking shop. The stamper may also discuss the mold number, referring to the mold used by the company to make the product. This can be useful for matching replacement parts, as people can use the mold number to get an exact replacement.

Manufacturers can apply the heat number even if the law does not require it because it can be a useful tool for tracking materials. As long as the company maintains up-to-date records, it should be able to search for any piece of metal by heat number and provide information about its origins. This can be useful for tasks such as accident forensics, where investigators may want to learn more about a particular metal product to see if a problem with the metal contributed to the accident. Heat numbers are also useful for recalls, allowing people to identify a bad batch of metal and send a notice to the public.




Protect your devices with Threat Protection by NordVPN


Skip to content