Specification
Bronze Weight and Wall Thickness: How to Spec It
Weight is what you are really buying in bronze. How wall thickness, solid or hollow casting and honest tolerances belong in a wholesale spec sheet.
Two censers can both be 60 cm tall and one can weigh half what the other does. Height is what a photograph shows; weight is what you are buying. A spec sheet that asks only for size leaves the most expensive variable to the supplier. Here is how to put wall thickness, weight and honest tolerance into a wholesale order.
Why does the same size piece arrive at two different weights?
Because nothing in a size number fixes how much metal goes into the piece. Wall thickness, solid or cored hollow, and how far the surface is chased all move the weight without changing an outside dimension. A thin-walled piece sells at the same catalogue size and costs the maker far less bronze. So a sheet listing sizes only is not a spec: two foundries answering the same list can be quoting different products, and the buyer finds out when the crates open.
What wall thickness should I ask for?
Ask for a figure, and ask where it is measured. Ours run about 5 mm through the body of a censer and around 8 mm at load points — feet, handles, rims, the neck where a lid seats. Those are where a piece fails when metal is stretched thin, and where a thin casting still looks right from the front. If a supplier will not put a millimetre figure on paper, that is your answer: a foundry that pours its own metal set the cores and knows.
Solid or hollow: which do I want, and where?
Hollow is not cheap and solid is not automatically better. Large vessels and censer bodies are cored hollow because a solid one would be unliftable and would cool unevenly, a defect in itself. Small figures, finials, crane heads and feet are cast solid because there is no useful cavity in them. What matters is that the choice is written down and is yours, because a container of bronze hits its weight limit long before it runs out of space.
How much weight and size variation is normal?
Every piece here is poured into a sand mould that is broken open to release it, so no two come out identical. Across a five-piece set we treat a variation of 1–3 cm as normal; anything over 5 cm is a defect and is recast at our cost. Our guide to tolerances in hand casting covers where that variation shows and where it does not. Weight moves with it, and a foundry offering a zero tolerance is not telling you how it works.
What belongs on a spec sheet I send to a foundry?
Six columns, filled in for every line item. Send it as your own document rather than accepting a supplier’s list, so every quote comes back in the same shape. The figures below are ours, from the specifications page; use them as the format, not as your order.
| Item | Nominal size | Measured size | Wall | Weight | Tolerance |
|---|---|---|---|---|---|
| Censer, size 60 | 60 | about 57 cm tall | 5 mm body, 8 mm feet, handles | weighed at sample | 1–3 cm |
| Pair of cranes | matched | 5–7 cm taller than the censer | 5 mm, solid legs | weighed at sample | 1–3 cm |
| Pair of candlesticks | matched | 12–15 cm shorter than the censer | 5 mm, 8 mm at base | weighed at sample | 1–3 cm |
| Incense bowl | matched | about a third of censer height | 5 mm | weighed at sample | 1–3 cm |
| Five-piece set, size 65 | 65 | — | 5 mm, 8 mm at load points | about 36 kg complete | over 5 cm recast |
Note what the weight column does not say. We publish the one set weight we have actually weighed and write “weighed at sample” elsewhere, rather than filling the column with tidier numbers.
How do I check weight on arrival?
A bathroom scale, a tape and the packing list cover it. Five checks:
- Weigh whole crates against the packing list before unpacking, photographing the reading with the crate mark visible.
- Weigh one full set per size against your approved sample, not the catalogue.
- Measure the piece, not the box — foot to highest fixed point, so everyone measures alike.
- Tap the wall low on the body and again near a rim. A thin casting rings longer and higher, audible without a gauge.
- Press the load points — a foot or handle that flexes under finger pressure is not an 8 mm section.
Do this in full on the first lot, then on a sample of each lot. To have it done before the goods leave Vietnam, our guide on pre-shipment inspection sets out what an inspector weighs and photographs.
Does the alloy change the weight?
Yes, and buyers routinely compare pieces that are not the same metal. A “bronze” piece from one supplier and a brass piece from another differ in weight and colour at the same size — our guide on bronze, brass and copper sets out how. Put the alloy on your sheet beside the wall thickness, or the rest of it measures the wrong thing.
Questions buyers ask
Is hand-cast bronze accurate to weight?
Not to the gram. Ask for the weighed figure from your approved sample and agree a band around it. A supplier promising an exact weight every time is describing machine work.
What if the goods arrive lighter than the sheet says?
Weigh a crate before unpacking, photograph the scale and compare with the approved sample. A whole lot running light is a specification failure, not variation — that is what the acceptance clause is for.
Why will a foundry not give a zero tolerance?
Because the mould is destroyed at every pour and rammed by hand each time. We publish 1–3 cm as normal and over 5 cm as a defect, so there is a number to hold us to.
How do I measure wall thickness?
At an open edge — a rim, a foot opening, the underside of a lid — with a caliper. Closed sections need a gauge, so ask for the figure and check where metal shows.
Is a hollow piece lower quality?
No. Large bodies are cored hollow on purpose, for weight and even cooling. What matters is that the wall is the thickness you specified and load points carry more metal.
Send us your spec sheet. Send your sizes with the columns above blank and we fill in wall, weight and tolerance line by line, then quote against it. Production runs 21–30 days after sample approval. Use the request a quote form or WhatsApp at +84 926 199 999; a quotation comes back in two working days.