An anodising price is a price against a specification. Where the specification is not stated, each shop has to assume a coating thickness, a sealing method and an acceptance standard before it can quote at all — and different assumptions produce different numbers. This tool helps you set out all three, so that the shops you approach are pricing the same job.
Two quotations for what looks like the same job can differ widely without either being wrong. If one has priced a 20 micron coating with a nickel seal and a dye-spot test, and the other a 10 micron coating with a hot water seal and no test, the two numbers are answering different questions. Setting the specification out is what makes them answer the same one.
| Coating grade | AC 25 takes roughly five times the bath time of AC 5, and five times the power. If the grade is not stated, the shop has to assume one in order to quote at all, and you will not know from the price which one it assumed. |
| Alloy | 6063 anodises clean and even. 6061, high-copper and recycled-content alloys are less predictable. Without the alloy, a shop can only price for the straightforward case, and any difference shows up after the metal is in the tank rather than before. |
| Sealing and its test | Sealing quality cannot be seen. A correctly sealed coating and an under-sealed one look identical until they are tested or until they weather. Naming the test is how both sides can be confident it was done. |
| Contact-mark zone | Not a defect — a physical necessity of racking. In our experience an unagreed contact mark on a visible face is among the most common rejection disputes, and it is entirely avoidable by agreeing the zone in writing. |
IS 1868 grades state minimum average thickness in microns, and parallel the AA grades in ISO 7599, which makes equivalence claims straightforward for export documentation. CPWD work typically calls for AC 15 interior and AC 20 or AC 25 for exterior facades. Coastal and heavy industrial exposure should be at AC 25. If your customer specified AAMA 611 or MIL‑A‑8625 instead, put that in the additional requirements field — do not try to translate it yourself.
ISO 2143 dye spot is the routine works test and is adequate for most job work. ISO 3210 acid mass loss is the referee test when a batch is disputed. ISO 2931 admittance is the most sensitive of the three and is still uncommon in India. If your application genuinely needs it, say so early, and expect to discuss it with the shop rather than simply issue it.
We would suggest asking each shop to confirm the specification back to you in writing before work starts, including the grade, the sealing method and the sealing test. Good shops are generally happy to do this — it protects them as much as it protects you.
If your customer has handed you a standard you have not worked to before, or you are choosing between job shops and cannot tell which can actually hold the grade, send us the drawing. We have qualified and audited anodising lines against IS 1868, AAMA 611 and MIL‑A‑8625, and the answer to “can this shop do it” is usually visible in their tank schedule and their sealing records.