Faucet Polishing Robot: Brass Taps to ABB Cells

A kitchen or bathroom tap is usually cast or forged and machined, then ground, polished and buffed until the surface is smooth enough to plate. That last stretch has always been the dirtiest and most skill-dependent part of the job. A faucet polishing robot holds the part against belts and wheels with a controlled force, so the finish comes out the same on every piece. This post looks at how brass taps were finished by hand, how dedicated machines and then robots took over, where ABB's force-controlled robots fit today, and what still makes polishing hard to automate.

A historic brass shower mixer with two cross handles, shown at an exhibition in Bad Schussenried in 2011. Photo: AustinTowers / Wikimedia Commons (public domain)

How brass taps were buffed by hand

Taps as we know them are a 19th century product. Edward Chrimes of Rotherham invented the high-pressure tap in 1845, and separate hot and cold taps of that kind are still common in older buildings. In 1880 Thomas Campbell of Saint John, New Brunswick, patented a mixer tap. Most of these fittings were cast in brass, and before they left the works someone had to take the casting marks and file lines off and bring the surface up to a shine, one tap at a time, at a spinning wheel.

An old cast brass tap with a T handle. Photo: Assianir / Wikimedia Commons (CC BY-SA 3.0)

The trade used two related steps. In polishing, the abrasive is glued to the work wheel and removes metal fairly aggressively. In buffing, a loose abrasive compound is applied to a softer wheel, which leaves a smoother, brighter finish, and most mirror finishes are actually buffed. Both were done by workers pressing parts against wheels by hand, as in this 1942 photo of women buffing small aircraft engine parts at an Allis-Chalmers supercharger plant. A good polisher judged pressure and angle by feel, and that feel took years to learn.

Women buffing small aircraft engine parts at an Allis-Chalmers supercharger plant, October 1942. Photo: Ann Rosener / Library of Congress via Wikimedia Commons (public domain)

As fittings became a mass product, the work moved into bigger plants. Hansgrohe was founded in 1901, and in 1936 Friedrich Grohe took over a hardware factory in Hemer and turned it to sanitary faucets alone. In 1962 Grohe acquired the rights to build the Moen mixing faucet, which mixes hot and cold water with a single lever, six years after launching the Skalatherm, an automatic mixing valve with a built-in thermostat. Polishing in plants like these was done by hand or on dedicated polishing machines built for one part shape. Those machines were fast but inflexible, and each new faucet design meant new tooling.

Workers polishing capsules at the Deventer capsule factory in the Netherlands, 1919. Photo: Nationaal Archief via Wikimedia Commons (CC0)

Force-controlled robots in faucet plants now

In an article on robotic polishing, ABB engineers lay out why robots took over much of this work: polishing has traditionally been done by hand or by dedicated machines, and robots offer more flexibility than the machines and better economics than manual work. They also note that skilled polishers are increasingly hard to find, because fewer people want to work in a dirty polishing environment, and that consistent quality across shifts and workers is very hard to reach. In a typical cell, the robot picks up the faucet body and moves it across a series of belts and buffing wheels.

A robot arm holds a guitar body against a buffing wheel at the C.F. Martin guitar factory, 2024, the same method faucet cells use. Photo: Henrysz / Wikimedia Commons (CC BY 4.0)

The core technology is force control. With position control alone, a robot follows a path, but it cannot guarantee a steady contact force as the belt wears or a casting varies. ABB's Integrated Force Control lets the robot feel the pressure through a force sensor and adjust its path so that it holds a constant force, even when the exact position of the surface is unknown. It can also change speed on input from the sensor to follow edges, which ABB uses for deburring complex shapes. Our post on ABB robot use cases lists other finishing jobs.

An ABB IRB 6700 grinding a steel part in Teqram's EasyGrinder cell at Ancofer. Photo: ABB

On 28 September 2026, ABB Robotics launched E-Device, a compact safety interface that lets customers use their own tablet or PC to operate, program and monitor OmniCore robots, with a physical emergency stop and a three-position enabling switch. ABB says E-Device meets the new ISO 10218:2025 safety standard. For a polishing line, that means a program built and simulated offline in RobotStudio can be carried on the same tablet to the cell, and AppStudio, ABB's no-code tool for application screens, can give operators a simple polishing menu. For a dusty, wet cell, the IRB 1300 is available with Foundry Plus 2 protection against water and dust.

An ABB IRB 1300 with Foundry Plus 2 protection, built to handle water and dust. Photo: ABB

Where faucet finishing goes next

Home buyers mostly notice the finish. Faucets now come in chrome, nickel, brass and dark coatings, and a shop that offers one model in five finishes runs smaller batches of each. Every one of those finishes starts from the same polished base metal, so a scratch left on the brass body shows through the coating on the buyer's sink. That favours robots, which can change programs between batches, over dedicated machines that need retooling, and it favours force control, which lets one cell handle many shapes without perfect fixtures.

A brass tap with a cross handle on a bathroom basin. Photo: Tamorlan / Wikimedia Commons (CC BY-SA 3.0)

In factories, the next step is less programming time. Teaching a robot every polishing path by hand is slow, so engineers build and simulate the paths offline in RobotStudio before the cell is built. Larger parts can move to bigger arms, the way an ABB IRB 6700 grinds steel parts in Teqram's EasyGrinder cell at Ancofer, and tablets with E-Device let one engineer move between several cells on a line. The no-code programming tools aim at the same goal from the operator's side.

Engineers with an ABB OmniCore controller and robot cell. Photo: ABB

Several problems are still open. Polishing cells are dirty, belts wear quickly, and abrasive dust needs extraction and robot protection, which adds cost. A faucet maker also needs people who understand both polishing and robot programming, a rare mix in many plants. Small makers with short runs may still find hand polishing cheaper. For high-volume brass and stainless fittings, though, the shortage of skilled polishers that ABB describes is a strong push towards force-controlled robot cells.

A brass bath and shower mixer tap in a London bathroom, 2007. Photo: Gürkan Sengün / Wikimedia Commons (CC BY-SA 3.0)

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