Batch and heat

The heat is the quantity of steel that a steel mill has produced in a single melting process. It has a uniform chemical composition and a heat number, which is stated on the mill certificate issued by the steel mill. The batch is the production quantity from one heat that passes through heat treatment and testing together at RS Randack and therefore has the same mechanical properties. Both numbers appear on the inspection certificate and in the marking of the parts.

Why the heat matters so much

The strength, toughness and corrosion resistance of a steel depend on its chemical composition. Two bars of the same size from different heats can differ on the certificate, even with the same material number. A certificate is therefore valid only for the heat from which the lot was made. If material is mixed, the certificate is worthless.

Single-heat supply at RS Randack

At goods receipt, every bundle is given a material tag with heat and batch, the ends of the bars are colour-marked, and identical diameters from different batches are never stored in the same rack compartment. The works order states the heat from which the parts may be made; the saw operator checks the bar against it before cutting. Different batches never go into the same container, not even for shipping. On request, we produce a line item from a single heat, which affects material procurement for large quantities.

What you should specify

Whether you require single-heat supply per line item, whether the steel mill’s mill certificate should be supplied and what marking the parts should carry.