--- title: "Hard Anodising Plant for Cookware — Setup, Rack Marks & Alloy | Saravana Consultancy" description: >- Setting up a hard anodising line for cookware in India: why it is not a smaller profile line, where rack marks land, why 1050 and 3003 anodise differently, PTFE topcoats, sealing and food contact, and what the plant costs. canonical: "https://www.saravanaconsultancy.in/applications/cookware-anodising-plant" source_url: html: "https://www.saravanaconsultancy.in/applications/cookware-anodising-plant" md: "https://www.saravanaconsultancy.in/applications/cookware-anodising-plant.md" last_modified: 2026-08-20 --- # Hard anodising for cookware — the plant, the rack mark, and the alloy A cookware line has to survive a steel spatula and look identical to the piece beside it on the shelf. Most of the reject cost comes from the second job, and almost all of it is decided before commissioning. Hard anodised cookware is a finish that has to do two jobs at once: survive a steel spatula for years, and look identical to the piece next to it on a shelf. Most of the reject cost on an Indian hollowware line comes from the second job, not the first. ## Why a cookware line is not a smaller profile line A profile line is sized by the longest extrusion it must dip. A cookware line has no such driver. Vessels hang from a rack, so **tank length is set by the rack** — typically around 2.3 m — and **tank width by the largest vessel diameter plus clearance**. A 360 mm kadai and a 280 mm tawa need the same tank length and different widths. Two other differences follow from the product being visible: ### An extra rinse stage Drag-out that would be invisible on a window section leaves a mark on a pan that a buyer holds up to the light. Hollowware lines carry one more rinse than the equivalent profile line, and it is not optional. ### Bespoke fixtures A curved shell has to be held rigidly, conduct current evenly, and be touched only where the customer will never look. That is a designed fixture, not a standard rack, and it costs roughly 40% more per square metre of loaded area. ## The rack mark is the whole problem Every anodised part carries a contact point where current entered it. On an architectural profile that mark sits inside a glazing pocket and nobody sees it. On a tawa, there is nowhere to hide. Full detail on where the contact should land, and how to read a burn against a witness mark, is in [rack marks on anodised cookware](/blog/rack-marks-anodised-cookware). **Contact-point placement is a design-stage decision.** Once the line is commissioned and the fixtures are made, your options are jig rework or scrap — and by then the tanks are in the ground. The right time to decide where the mark lands is while the rack is still a drawing: on the rim underside, on a handle boss, on a spot the base plate covers. ## Alloy is not a detail Cookware is pressed and spun from **1050, 1060 and 3003**, and sometimes cast — not the 6063 that most anodising literature assumes. These alloys anodise differently: the coating grows at a different rate, takes colour differently, and responds differently to sealing. A process sheet copied from an architectural line will not hold on a cookware line, and this is the single most common reason a new hollowware plant produces inconsistent colour in its first six months. Incoming alloy variability is worse again with recycled input. If your supplier's chemistry moves between lots, your colour moves between lots, and no amount of bath control will recover it. See [alloy selection for anodizing](/guide/aluminium-alloy-selection-for-anodizing). ## Non-stick over hard anodise The premium cookware stack is hard anodise plus a PTFE topcoat. When non-stick peels off hard anodised cookware, the failure is almost never the PTFE itself — it is the surface underneath: a coating sealed too hard for the resin to key into, an under-etched surface, or contamination between the two steps. The four real causes, and how to tell them apart, are in [why non-stick peels off hard anodised cookware](/blog/non-stick-peeling-hard-anodised-cookware). The process detail is in [hard anodizing with PTFE](/blog/hard-anodizing-ptfe) and the [process and ASTM D4060 wear test methods](/blog/ptfe-impregnation-hard-anodize-process-test-methods). ## Food contact and sealing A properly sealed anodic layer is inert and stable, which is why anodised cookware is used at all. The corollary is that **sealing quality is a food-safety parameter, not just a durability one**. Under-sealed coatings are porous, hold residues, and stain. Sealing contact time is also the first thing cut when a line is chasing throughput, which makes it the first thing to audit when quality drifts. See [sealing methods compared](/blog/anodize-sealing-methods-comparison) and [nickel acetate sealing](/blog/nickel-acetate-anodising-sealing-india). ## What a cookware line costs Set the archetype to **Hollowware** in our [plant cost and payback calculator](/calculators/anodizing-plant-cost) and it will size tanks from the rack and the vessel diameter rather than from a part length, add the extra rinse, and price fixtures at the hollowware rate. If you are a cookware maker currently sending work out, set the mode to **Captive** and enter the rate your job shop charges you today. That number, not a job-work realisation, is what the line earns you back. ## The number most people never calculate On a visible-surface product, reject rate costs twice: the revenue is lost and the power, chemicals and labour were already spent on the piece that gets scrapped. The calculator now puts an annual figure on each percentage point of reject rate at your configuration. On most hollowware lines that number is larger than any equipment upgrade being considered at the same time — and it is set by fixture design and alloy discipline, both of which are decided before commissioning. If you know the plant you want and need the numbers before a serious internal conversation, the [plant setup snapshot](/services/plant-setup-snapshot) is a ₹2,500 written feasibility note in three working days, credited against Phase 0.