A furnace number can be divided into several batches, the same number of the same batch of steel furnace can be different sizes, but the material is not the same level must be the same plate. Different batches of the same heat number plates can be different sizes, but the material is not the same level must be the same batch number plate is very simple, such as API 5L Gr.b, many manufacturers has this material, certainly has a lot of production out of the oven, and then shipped when necessary to send by batches, each batch will have a fat batch number. Therefore, the same batch number, different heat number is likely, but if there is quality problem, you can put there to check out the furnace problem. Similarly batches, each furnace in the process, the allowed range there will be some small differences can have a batch furnace, with about normalizing heat treatment: heat treatment along with a number count. Quenched: Each operator group (a group of more than one cut can be considered).