What kansa is, where it is made and what science says about it

Kansa is bell metal: a bronze of copper and tin, with far more tin than most bronzes. The usual figure is about 78% copper and 22% tin, or roughly four parts to one.

Studies of Indian pieces agree on the range. Banglapedia describes Bengal's kansa as a beta bronze of about 22.5% tin. Kerala bowls studied by the metallurgist Sharada Srinivasan were about 23% tin.

Tin is what makes kansa ring. More tin makes the metal stiffer and lengthens the note after a strike, which is why bells are cast from the same alloy.

The same tin makes it hard but brittle. A 2017 foundry study of bronzes with 20–24% tin found that hardness rose with tin, while tensile and impact strength fell.

India has worked bronze for more than four thousand years. The National Museum in New Delhi calls the Harappan civilisation a Bronze Age culture, and displays the bronze “dancing girl” from Mohenjo-daro.

Harappan bronze was not kansa, though. The archaeologist Vasant Shinde notes that only 30% of 177 copper objects tested from Harappa and Mohenjo-daro were alloyed, with tin between 1 and 12%.

High-tin bronze comes later. Srinivasan and Ian Glover trace high-tin bronze objects in the subcontinent from the 1st millennium BC to the present day, mostly in South India.

Bengal has its own long record. Banglapedia dates kansa there to the early historic period and notes kansa vessels of Bengal origin found as far away as Thailand.

In Odisha, the state's One District One Product listing names Kantilo, in Nayagarh district, for brass and bell-metal work. It also records the custom of giving bell-metal utensils at a daughter's wedding.

In West Bengal, the Murshidabad district administration lists Khagra, Berhampore, Kandi, Baranagar and Jangipur for bell-metal and brass utensils. Its page also notes buyers moving to stainless steel, plastic and ceramics.

In Assam the metal is called kanh, and Sarthebari in Barpeta district is the main centre. The state Industries Department counts about 1,507 artisans there.

Only one of these centres holds a geographical indication (GI). IP India's register lists Sarthebari Metal Craft as registered; we found no GI for kansa utensils from Kantilo or Khagra. Related metal GIs from other states are below.

Two methods run through every centre: casting metal in moulds, and beating it into shape. Odisha's district listing names both, and Sarthebari's workshops use a little of each.

The Assam Industries Department describes the Sarthebari sequence step by step:

• Melt: metal, often collected scrap, is melted in a crucible called a muhi.
• Cast: the melt is poured into moulds (aak) to make thick round blanks called guti or pitha.
• Roll: rolling mills press the blanks into sheets (fali) and discs (chak). This is the only machine step.
• Shape: artisans form the sheets and discs into vessels by hand, with anvil (niyari) and tongs (sara).
• Finish: pieces are turned on a hand-operated lathe (kun), scraped with a blade-like tool, then buffed.

Ayurvedic texts call kansa kamsya and class it as a mixed metal, an alloy of copper and tin. A 2011 review of the Charaka Samhita notes that Charaka used it for the nozzle of an enema device.

The clearest food references come from later texts. The 17th-century Bhojanakutūhala, a work on diet and cooking, credits bell-metal vessels with sharpening the intellect, improving appetite and clearing “blood and bile”.

The Rasaprakāśa-sudhākara, a Sanskrit text on metals in medicine, says all foods become wholesome in a bell-metal vessel except sour food, ghee and leafy vegetables.

These are statements of tradition, written long before laboratory testing. They show how highly kansa was valued, not what it does in the body.

No clinical trial has tested eating from kansa. Our PubMed searches in October 2026 for “kansya” and “bell metal” found no study of kansa tableware and health.

The nearest evidence concerns copper surfaces. A 2011 review in Applied and Environmental Microbiology reports that copper alloys kill bacteria on contact, more effectively as copper content rises.

Those findings come from laboratory tests and hospital fittings, not plates of food. Kansa is a copper alloy, but we found no study measuring germ-killing on a kansa thali in use.

Water studies stop at the same place. In 2007, Tandon and colleagues found faecal bacteria fell substantially after 12 hours in a brass vessel, but not in an earthen one; we found no kansa equivalent.

The documented risk is lead. In 2024 a New York family's blood lead rose after using imported kansa and pital vessels. CDC notes lead can be added to such metalware to ease working or cut cost.

Kansa is tableware first: thalis, katoris (watis), glasses and serving bowls. Serve a meal on it, then wash it; don't keep food in it overnight.

Sour food needs care. The US FDA Food Code bars copper and copper alloys from contact with food below pH 6, such as vinegar or fruit juice. WHO's guideline for copper in drinking water, set mainly against stomach upset, is 2 mg/L.

• Everyday thali food, such as rice, roti, dal, dry vegetables and sweets, can be served on kansa.
• Pickle, tamarind, lemon and curd can go on the plate for the meal, but don't leave them sitting.
• The Rasaprakāśa-sudhākara also leaves ghee off its list; that is tradition, not tested advice.
• Never drop kansa on stone. Banglapedia notes that kansa water bowls were brittle.
• Stack thalis with a cloth between them, and don't knock pieces together in the sink.
• Wash by hand with mild soap, dry at once, and keep it out of the dishwasher.
• Buy from a maker who states the metal, and ask for a test report if you need certainty.

If you are choosing between kansa and steel for daily dining, our kansa vs stainless steel guide compares weight, breakage, care and cost.

At Hastimal Valchand (HV) we supply kansa thalis, watis, glasses and dinner sets from Thakurdwar Road, Mumbai. Each is listed with its code in our kansa range.

This article is general information, not medical advice.