Every steel supplier says they offer traceability. Very few can answer the question that actually tests it: for this specific bundle in my yard, which mill heat did it come from, which line drew it, on which shift, and where is the certificate?
What a heat number is
Steel is made in batches. A heat is one melt — one furnace load, cast and rolled together. Every bar from that heat shares the same chemistry, because it was the same liquid steel. The heat number identifies that melt, and it is the only identifier that connects a physical bar to a set of certified properties.
Lose the link between bar and heat number and the certificate becomes a piece of paper about steel you can no longer identify.
Where the chain usually breaks
The break is rarely at the mill. It is in the processor's yard. Coils are received, stacked, blasted, drawn and bundled — and somewhere in that sequence the paperwork is kept in a register while the material moves independently. By dispatch, the connection between a specific bundle and a specific heat is a matter of recollection.
The other common break is re-keying. The heat number is written on a GRN, copied to a production sheet, copied again to a challan. Each transcription is an opportunity for a digit to change.
What a working chain looks like
At Kalika the heat number is entered once, at goods receipt, into the ERP — together with the weighbridge slip and the mill certificate. From that point it is inherited, never re-typed.
- At drawing, the production record links the heat number to line, shift, operator, die and date — captured at the time of production.
- At bundling, a QR tag encoding heat number, grade, size and production reference is applied to the bundle itself.
- At dispatch, the heat number prints on the delivery challan.
- With the consignment, the Kalika test certificate carries the same heat number alongside the original mill certificate.
What an IATF audit asks
An IATF 16949 auditor will typically sample a batch of your finished components and ask you to trace it back to incoming material and its heat. If your supplier can only produce a general certificate for the grade, the chain stops at your gate and the finding is yours, not theirs.
Traceability also pays for itself outside the audit room. When a concern arises in service, the practical question is how much material is affected. With heat traceability the answer is bounded to a specific batch. Without it, the answer is everything you shipped in the period — which is the difference between a contained issue and a general recall.
Written by the technical team at Kalika Enterprises, Waluj MIDC. Guidance here is general; the values that govern your part are those on the test certificate supplied with your consignment.