In this guide 6 sections
Heat number traceability links the mill certificate to the billets cut from that heat, the forging lots made from those billets and the parts you ship. Record the heat at each hand off, and a customer audit becomes a search instead of a hunt through folders.
What the chain must connect
A traceable forging has four links: the heat from the steel mill, the billets sawn from it, the forging lot and the shipment. Break one link and the audit fails.
Auditors from automotive and rail customers usually start at the part and work backwards, asking for the lot, then the heat, then the certificate. Practise answering in that order.
Draw your chain on one page, then mark every place where the heat number is stamped, tagged or typed today and every place where it quietly goes missing. Try it on paper first.
- Mill test certificate with heat number
- Billet batch cut from that heat
- Forging lot and press shift
- Heat treatment load and final inspection
- Shipment, invoice and customer part number
Receive the certificate properly
The certificate arrives with the bar, often as a scanned PDF, so check grade, chemistry and heat number against the bar tag before accepting the material.
Store the file against the heat record rather than a general folder, and name it by heat number so that one search opens the certificate at once.
Hold any bar that arrives with a missing tag or a number that disagrees with the certificate, and keep it in a quarantine rack until quality clears it. Untagged bar is how traceability dies.
Keep the heat alive through cutting and forging
Sawing is the weak point. Billets from three heats can end up in one crate, so mark each crate with its heat and scan or enter that number at the saw.
At the press, the operator confirms the crate and the heat before the first strike, and the forging lot then carries that heat into every record that follows.
If heats mix in one lot by accident, split the lot and never average their chemistry, because a split costs minutes while a mixed lot costs a customer.
- Tag every crate with heat and billet count
- Confirm the heat at the press before starting
- Never combine two heats under one lot number
- Hold leftover billets with their tag intact
Carry the number through outside processes
Heat treatment, shot blasting and machining are done by vendors, so send the lot number and heat on the delivery note and require the same on the packing slip.
Parts lose identity in the basket. Ask the vendor to keep baskets by lot and to report the furnace batch or load number for each, so the heat treatment record ties to your lot.
Record the returning quantity. Any gap between pieces sent and pieces returned is either scrap you have not booked or a hole in the trace that an auditor will find first.
Prove it in minutes
Test the chain with a mock audit. Pick a shipped part at random, then find its lot, its heat, its certificate and its inspection record while a colleague times you with a stopwatch.
Write down every drawer you opened and every colleague you phoned, because those gaps are the fields to capture first. Repeat it every quarter, using a different customer part each time, a different heat, a different press shift and a different furnace load.
Done well, a query on a suspect heat names the exact forging lots, the parts made from them and the shipments that must be recalled, within minutes.
Heat to part trace worksheet
Five columns span this single worksheet: heat number, certificate file name, billet batch, forging lot, heat treatment load and shipment reference. Below them sits a mock audit box that records the part picked, the time taken, the cabinets searched and the gaps found.
Open a blank worksheet to printQuestions owners ask
What is a heat number?
A heat number is the identifier a steel mill gives to one melt, and every bar from that melt shares the same chemistry, so it anchors the trace. The mill prints it on the certificate.
Do we need to scan barcodes?
Not at first. Typed heat numbers from a tag work if the entry happens at the crate, the saw and the press, and barcodes reduce typing mistakes once volumes grow.
How far back should records be kept?
Follow your customer contract and any standard your industry uses, because many customers set their own retention period in the supplier quality manual. Check before you archive anything.
What if a heat is found faulty after shipping?
Search the heat, list every lot and shipment linked to it, and tell the customer exactly which parts are affected. A clean trace limits the recall.