Stencils, Tags and Shipping Marks: What We Put on Your Steel Before It Leaves the Yard

Every few months a buyer sends us a photo of a container floor covered in coil bundles and asks which one is which. Nine times out of ten the answer is somewhere in the paperwork but nowhere on the steel. The packing held up, the coils are fine, and nobody ever told us what to paint on the outside.

A mark has four readers, and they never talk to each other

A shipping mark is not decoration. In practice it gets read by four people. Your customs broker reads it to match the entry against the invoice. Your warehouse reads it to put the coil in the right bay. Your production planner reads it to know which coil to cut first. And your quality person reads it two years later, when a claim needs to be traced back to a heat number and a mill certificate.

If the mark only says "GALV COIL 0.5" it works for the planner and fails everybody else. That is how coils sit in the wrong bay for six months and then get consumed in the wrong order.

What we print when nobody sends a spec

Our default set is coil or bundle number, grade and standard, size, net and gross weight, purchase order reference, destination port, and our own name. On a galvanized steel coil that reads something like DX51D+Z, 0.50 x 1000 mm, Z275 coating, 4.85 t net, plus a coil ID that leads back to the mill certificate.

Grade and coating class matter more than buyers expect. "Galvanized" on its own covers everything from Z100 to Z275 and from a 0.30 mm base to a 3.0 mm base. Two bundles can look identical under a warehouse light and behave nothing alike in a press brake or on a roofing purlin. The same is true of a hot rolled carbon steel coil, where Q235B and Q355B are the same colour and nowhere near the same animal.

Stencil, label or wired tag

There are three ways to put a mark on and they are not interchangeable.

Paint stencil on the outer wrap. Cheap, quick, and it handles humidity well. The catch is that the mark lives and dies with the wrap. If the film tears during handling, the identification goes with it. We use stencilling for the big information: port, bundle number, size.

Adhesive label. Perfectly good on a dry, clean wrap at room temperature. Less good on a cold coil in January or a dusty surface. If you are labelling, the label goes on the film, not on the steel.

Tag wired to the bundle. The most durable option for ocean freight and container stacking. A plastic or thin metal tag on nylon or wire, threaded through the coil eye and around the bundle so that whatever way the bundle lands, something stays readable. This is where we put the coil ID and the heat number, because that is the pair somebody will need long after the wrap is gone.

One thing we avoid is a marker pen straight onto the coil face. On oiled or passivated steel the ink either wipes off in transit or leaves a residue your painter has to clean off. Marks belong on the wrap or on a tag.

The same problem shows up in flat products

A stack of corrugated roofing sheet in mixed colours and thicknesses is genuinely awkward to sort on site when the bundles are unmarked, and colour is not a reliable way to separate 0.45 mm from 0.50 mm. On profiled sheet we mark the bundle end and put a tag under the strapping as well.

Colour adds a second dimension. Give us the RAL number and tell us which quantities have to be installed together, and we will mark the batches so they can go on separate elevations instead of being mixed across one wall. With PPGI colour coated coil we have seen jobs where two production batches of the same RAL differ just enough to be obvious in raking afternoon light.

What we actually need from you

The fast route is a one-page marking specification attached to the purchase order. It does not need to be formal. We need the exact text you want printed, character by character, including whether you want Latin letters or your own script. We need to know where it goes, and whether you want a barcode or QR code and what data sits inside it.

If you would rather your own name appeared on the coil than ours, say so early. Some buyers want the supplier visible. Others want a neutral bundle because the coil is resold under a different brand. Both are easy, but only if we know before the yard starts wrapping.

The three misses we see most

First, a wrong or missing purchase order reference on a mixed container. When one shipment carries three orders, every bundle needs the order it belongs to, not just the shipment number. Second, marks specified for the outer wrap only, on bundles that will be stacked four high so that only the top one can be read. Third, no heat number reference anywhere. That is the one you will want when a question comes up twelve months later and nobody can say which mill run it came from.

None of this shows up on a price sheet, which is probably why it gets skipped. It costs a few minutes in the yard, and it saves a container of guessing at the far end.

Zhishang Steel has always been a pioneer in custom steel and special supplies, and has been recognized for its efforts in enhancing work efficiency and product quality. In addition to ISO9001:2015 certification, we also adhere to strict quality policies and proprietary procedures. If you have any questions, please contact us to provide the best type of product solution for your pre-painted, coil coating metal process, we will closely support after-sales service to ensure that your subsequent problems can be solved in a timely manner, if you have any questions, please send email to info@zhishangsteel.com, we look forward to serving you.