What happens at the weighbridge: how yards grade your load, and what to do when it's downgraded

Most disagreements at a scrap yard come down to one moment: the grader looks at your load and calls it something lower than what you thought you’d brought. Knowing how the visit runs, what the grader is looking for, and where your leverage begins and ends makes that moment less costly — and usually avoids it.

How a typical yard visit runs

Layouts vary, but the sequence is much the same everywhere:

1. Weigh in. A vehicle load goes over the weighbridge full; a small load goes onto a platform scale in bins or bags.
2. Sort and inspect. Staff look through the material and separate anything that doesn’t belong.
3. Grade. Each pile is assigned a grade, which sets its per-kilogram rate.
4. Weigh out. The empty vehicle or bins go back over the scale.
5. Ticket and payout. You get a ticket listing each grade, weight and rate, and payment is made.
6. ID and records. The yard records who you are and what you sold.

That last step isn’t optional for the yard. In NSW, dealers must be registered with NSW Police, are prohibited from paying for scrap “with cash, cheque payable to cash or in kind,” and “must keep and maintain a record of each transaction when buying scrap metal, including the details of the person selling the scrap metal,” retained for three years (NSW Police). Victoria is similar: dealers must be registered second-hand dealers, “must not pay or receive cash for scrap metal,” and must record the seller’s name, address and ID along with “an accurate description, including its quantity and/or weight” of the metal (Consumer Affairs Victoria). Bring photo ID; a yard that doesn’t ask for it is the one to be wary of.

Gross, tare and net: why the ticket matters

The weighbridge produces two numbers. Gross is the loaded weight. Tare is the empty weight — vehicle, trailer or bins — taken on the way out. Net is the difference, and it’s the only figure you’re paid on. If the yard applies a stored tare from a previous visit instead of weighing you out, it’s fair to ask for a fresh one.

Scales used to price goods aren’t unregulated equipment. Under the National Measurement Act 1960 and the National Trade Measurement Regulations 2009, a business pricing goods by measurement must use an instrument of an approved type that has been “verified before use by a licensed technician,” and the National Measurement Institute employs inspectors who can visit a business “in response to a complaint or enquiry from a consumer” (business.gov.au). NMI’s guidance for those technicians states a trade weighing instrument must “operate within the limits of error permitted under the regulations” and be pattern approved (NMI).

For you, the practical point is the ticket. It should show gross, tare, net, the grade assigned to each portion, and the rate applied. Keep it; any later conversation starts with it.

How graders decide

A grade is a judgement about how much processing the metal still needs before it can be melted, and graders make it quickly, by eye and by hand. The things that push a load down are consistent across yards:

• Contamination. Non-metal material — plastic, rubber, timber, dirt — or the wrong metal mixed in. Steel screws through a bin of aluminium, or a brass valve left on copper tube, are the classic cases. The copper page covers where the lines between bare bright, #1 and #2 sit.
• Attachments. Anything bolted, riveted or welded on that isn’t the base metal: steel brackets on aluminium frames, motors still in their housings.
• Moisture and residue. Wet material weighs more than the metal in it; oily metal needs cleaning. Both justify a deduction.
• Mixed loads. A bin holding two grades is usually paid at the lower one. The yard won’t sort it for free.

The grader is pricing the pile for what it will cost to process, and the answer is only as good as the sorting you did before you arrived.

Which downgrades are fair, and which aren’t

Legitimate downgrades follow from that list: visible contamination, attachments you didn’t remove, obvious moisture, genuinely mixed material. If the grader can point to the problem in the pile, the call is usually right.

Less defensible reasons are vaguer: “it’s all going as #2 today” with nothing to show for it, a whole bin downgraded for one foreign piece that could be lifted out in seconds, a moisture deduction on plainly dry material, or a rate that differs from the board with no explanation. Those are the ones worth questioning.

What you can reasonably do on the spot

Your leverage is greatest before you’ve been paid and before the metal has gone into the yard’s bins.

• Ask for the reason. “What’s bringing it down?” is a normal question, and a good grader will show you.
• Ask for a re-sort. If a little contamination is dragging a large load down, ask whether you can pull it out and have the load regraded. Many yards allow this if it’s quick.
• Remove contaminants yourself. Knock the bracket off, cut the fitting off, tip the water out. Bring a few basic tools for exactly this.
• Split the load. Ask for the clean portion to be graded separately from the disputed portion.
• Take the disputed portion elsewhere. You can decline to sell part of a load and try another yard. Ring first; the city pages list yards near you.

What you can’t do is insist on a grade. The yard is the buyer and sets the grade it’s willing to pay; if you don’t accept it, your option is to walk. You can’t change your mind after the material has been tipped into the yard’s stock, and you can’t expect staff to sort a mixed load for you. That work is yours.

Preparing so disputes don’t happen

Most downgrades are decided in your shed, not at the weighbridge.

• Sort by metal, then by grade, into separate bins.
• Remove steel, brass and plastic from anything you’re selling as a single metal.
• Keep it dry and drain anything that holds water.
• Weigh it at home if you can and run the figures through the calculator so you have a realistic range in mind. Our methodology assumes yard-side grading, so well-prepared material should land near the top of that range and poorly prepared material near the bottom.
• Ring ahead, describe the load, and ask what grade it will likely land in.

When to take it further

A grading disagreement on its own isn’t a matter for a regulator; the remedy is to sell elsewhere. Two situations are different.

If you believe the scale is wrong — the net doesn’t square with a weight you took at home, or the weighbridge reads inconsistently between visits — that’s a trade-measurement issue. NMI takes measurement complaints on 1300 686 664 or at infotm@measurement.gov.au (business.gov.au).

If the dispute is about the transaction — you were paid at a rate other than the one agreed, a ticket was altered, or the yard won’t issue one — a state consumer body may help, provided you sold as a private individual. NSW Fair Trading, for example, will “act as an informal negotiator, at no charge” once you’ve been unable to resolve the matter privately, but can’t intervene in business-to-business disputes (Service NSW). Cash payments or a yard that skips your ID are for the registering authority: NSW Police in NSW, Consumer Affairs Victoria in Victoria.

In every case, the ticket is your evidence. Keep it, photograph the load before you tip it, and raise the problem at the weighbridge rather than in the car park afterwards.