Faucet Basics: Part 1 What are Faucets Made of?

For the money, a basic American faucet may be one of the best consumer values around. Designed to last a lifetime, all but the cheapest almost certainly will, and if they don't, the manufacturer will at least replace the defective parts.

Today's faucets are designed to survive very harsh conditions, including thousands of on-off cycles every year and hard water mineral build-up, and still give year after year of flawless service. And, if it does break, a faucet is usually designed to be serviced by simply replacing the defective parts — typically a screwdriver operation — without first having to uninstall the faucet.

A Rose May Always Be a Rose but a Faucet Is Not Always a Faucet

There is almost no language more confusing than Plumber-ese. Carpentry is several millennia old and has a very odd lingo indeed. But, that's almost to be expected from such a venerable calling. Plumbing, however, is barely 300 years old so it should be a little less complicated. It is anything but.

One of the most confusing terms in plumbing is the name of the device that controls the flow of water.

In North America, the most common term is "faucet". In England and the former Commonwealth nations, except Canada, the term is "tap". The two terms can be used interchangeably, along with "Spigot" and "valve".

In the U.S. a "faucet" usually refers to a decorative plumbing device used to control the flow of water inside the house. A "spigot" or "Bibb" is an outside faucet, and you probably have a few attached to the side of your house. It may also be known as a "hose Bibb", a "Bibbcock", a "sillcock", a "garden valve" or a "hose hydrant".

"Valve" is a nicely ambiguous term. Technically, a plumbing valve is any device that turns water flow on and off.

"A faucet is a "valve" Within the generally accepted use of the term but not all valves are faucets. A faucet also contains a valve — meaning that component of the faucet that actually regulates water flow, as distinct from other parts of the faucet such as the body, spout, handle, etc. that do not.

To add further to the confusion, a faucet "valve" is often confused with a faucet "cartridge" and the two terms are frequently used interchangeably.

A cartridge is a housing for a valve, in fact, it is often called a "valve cartridge" to distinguish it from other types of cartridges. But, while a cartridge always contains a valve, a valve is not always contained within a cartridge.

Many faucets still have valves that are built into the faucet body itself rather than into a removable cartridge. An outside spigot or hose Bibb, for example, is likely to have an old-style compression valve that is built into the faucet body.

The difference between a "mixing cartridge" and "mixing faucet" also causes confusion.

A mixing cartridge may be inside a mixing faucet but a faucet can mix without a mixing cartridge.

A mixing faucet is any faucet in which hot and cold water are blended together inside the faucet. Virtually all sink, tub, and shower faucets are mixing faucets.

Non-mixing faucets are not usually found inside the house. But outside, the hose Bibb is a non-mixing faucet. Unless you have done something strange to the plumbing, an outside spigot delivers only cold water.

Mixing faucets may have two handles, one to control the volume of cold water, and a separate handle to control the volume of hot water. Temperature is regulated by adjusting the amounts of hot and cold water entering the spout.

In a "mixing cartridge", water temperature is mixed inside the cartridge before the water is released into the faucet. These are always single-handle faucets that control the mix of hot and cold water and the volume of water. Water volume is independent of water temperature. The flow of water can be changed without changing the water temperature, and the temperature can be regulated without altering the volume of water flow.

If you have a single-handle mixing cartridge faucet in your house, try it. Turn on the water and move the handle right or left until you get the temperature you want. Move the handle up or back to increase the volume of water. Notice that the temperature did not change. Move the handle down or forward to decrease the flow of water, the temperature still does not change. Push the handle all the way down to turn off the water, then turn it back on again. The water is still set at the temperature at which you left it when you turned the faucet off.

It seems so simple that it's easy to forget that it took an authentic engineering genius, Al Moen, a large amount of creative thinking and nearly 10 years of experimenting to get faucets to work like this.

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Modern finishes are unlikely to flake or tarnish. Modern faucet plating and coating processes, including elec­tron beam physical vapor deposition — a process that is almost science fiction — can imitate anything: brass, nickel, pewter, even silver and gold. Epoxy coatings can keep that new finish looking new for a long time, with proper care.

Faucet valves rarely leak. Ceramic cartridge technologies have almost entirely banished the midnight drip, drip, drip. But, some of the best faucets still use older, tried and true, technologies that are proven to work well. These may require periodic maintenance, not an onerous or difficult task. For the old house purists, these are often the favored technologies. But, for the rest of us, the newer almost-no-maintenance ceramic technology is a better choice.

Unfortunately, the classic American faucet is increasingly not made in America. Some manufacturers have maintained substantial domestic manufacturing but many faucets are now made elsewhere — from China to the Balkans — and merely distributed by American companies under their own brands. for example, are long-established U.S. manufacturers that no longer manufacture any faucets in the U.S.

As with anything, some faucets are better than others, and price, while generally reflective of quality, is no absolute guarantee. You do not necessarily get a better faucet for more money.

All of the major faucet manufacturers, make mid-priced faucets that are lifetime or near-lifetime products. When you pay more than mid-price ($150-$350) then you are generally buying the cachet of high-style or custom hand finishing or both.

These are usually excellent faucets but not necessarily a quantum leap better than major-brand mid-priced faucets. They are produced in smaller runs or even made one at a time as they are ordered, so they do not have the cost savings of large production quantities. Thus the higher price. But, even these are often sharply discounted.

What's It Made Of?

Any material that will hold water can be used to make a faucet.

Faucets have been created from wood, glass, and ceramics, although these materials are not in common use. More typically, faucets are made from metals: pewter, copper, bronze, brass, stainless steel, and zinc alloys, although pewter and bronze are rare, found only in custom faucets. They can also be made of plastic.


The traditional material for fau­cets is brass.

Brass is prized for faucets because

About 80% of the brass used in new faucets was previously used to make something else.

Common yellow or "alpha" brass is about 60% copper and 30% zinc the rest being small amounts of other metals to give the brass specific properties.

A little antimony or tin might be added to retard a form of corrosion known as dezincification which can weaken brass over time. A pinch of iron or manganese makes brass harder and nickel refines the grain structure improving strength.

Aluminum may be added to make the brass stronger and more corrosion resistant. Admiralty and naval brasses used in salt-rich maritime environments contain a relatively high proportion of aluminum.

The copper in brass is anti-microbial — it kills germs, a fact that has been known since the rise of the Pharaohs, but how it does so has only recently been uncovered. Note 1 Many fungi (mold and mildew) and most bacteria cannot survive in the presence of copper. In tests on colonies of E. Coli bacteria conducted by the EPA, 99.9% of the colony was killed after two hours of exposure to brass.

Lead is added to make brass more malleable, less brittle, and easier to form.

In faucet brass, however, lead is dangerous to human health, and especially dangerous to children because it can leach into the drinking water that passes through the faucet.

According to the En­vir­on­ment­al Prot­ec­tion Agen­cy (RPA) lead can cause slowed growth, learning problems, hearing loss, anemia, hyperactivity, and behavior issues.

Before 2014, a faucet could contain as much as 8% lead and still call itself lead-free. Now the maximum lead content in a faucet is 0.25% (1/4 of 1%), basically just a bare trace of lead.

To ensure the absence of lead in the brass inside a faucet that is in contact with the water passing through the faucet, the faucet must be tested in a laboratory and certified lead-free. If it is not certified, it cannot be legally installed in a drinking water system.

Keeping Faucets Safe To find out more about how faucets are testeed and certified for safety, see Keeping Faucets Safe & Reliable

To comply with the new restrictions on lead, today's faucet brass uses other additives to ensure malleability. The most common substitute materials are bismuth and silicon.

Bismuth is similar to lead – right next to lead on the periodic table of elements – but it is not harmful to humans. Bismuth, however, is expensive. It is 300 times rarer than lead, even rarer than silver, which is the reason that bismuth-brass alloys are considerably more expensive than leaded brass.

Bismuth has several other problems. It is, unlike lead, a brittle metal, and requires a more precise casting process to preserve the of brass. The result of improper casting is illustrated by a 2012 recall by the Consumer Products Safety Commission of 63,000 azimuth-brass ball valves made in China for use in natural gas pipelines. They were much too brittle resulting in cracks and dangerous valve failures.

Bismuth is also an environmental issue. Brass alloyed with bismuth cannot be easily recycled with non-bismuth brass and must be kept separate to avoid cross-contamination of the materials.

Silicon has somewhat similar recycling issues, but not as severe. Some alloys can be recycled with ordinary brass. Its chief advantage is that it is plentiful. It is not, however, less expensive.

Silicon-brass is considered a high-strength brass. The silicon increases resistance to wear and corrosion. Its disadvantages are that it requires a higher casting temperature than ordinary brass and its hardness makes it much more difficult to machine.

Plumbers don't care for it because it requires a hotter torch and special techniques to solder without which "cold" solder joints may spring a leak. Nonetheless, it is increasingly popular among faucet manufacturers. One alloy, Eco-brass (C69300), is especially formulated for plumbing fixtures.

Stainless Steel Faucet

Photo: Moen, Inc.

Stainless steel is popular in kitchen faucets to exactly match stainless steel kitchen sinks. This is the Notch contejmporary kitchen faucet.

The better brass used in faucets is resistant to the dezincification process that occurs when the water passing through a faucet dissolves the zinc in the brass alloy resulting in brass that is porous and brittle. Tin or antimony is added to brass alloys to retard the dezincafication process. Brass that is resistant to dezincification (DZR brass) is tested and certified before being labeled DZR. Not every brass faucet is made of DZR brass, but those that are usually say so on the box.

Stainless Steel

The other common metal material for faucets is stainless steel.

Steel is harder than brass and has a higher melting point, making it more difficult than brass to cast and machine. But, it contains no lead, which in today's regulatory environment is a big plus. And, because it is stronger, castings can be thinner, saving on material.

The stainless steel used in faucets, 304 or 316 stainless contains 18% chrom­ium and 8-10% nickel. The nickel gives the steel a particular crystalline structure which increases its strength and malleability. The chromium (or chrome) helps the steel resist corrosion. A small amount of molyb­denum (2-3%) is added to 316 steel to better resist acids. Both alloys are austenitic steels meaning they are low- or non-magnetic.

Stainless 304, known as "food grade" stainless, is by far the more commonly-used alloy for making faucets. However, 316 stainless, known as "marine grade" stainless, has superior resistance to pitting, corrosion, and staining, particularly in acidic or salt environments. For kitchen faucets, it is considered the better material, but it is more expensive. Only a few manufacturers use it in their faucets, including which switched from 304 to 316 stainless in 2019, and which sells stainless kitchen faucets made in Italy by Super Inox S.R.L.

To make things a little more confusing, there are actually two commonly used grades of 304 stainless. The more widespread is 18/8, representing the proportion of chromium and nickel in the alloy: 18% chromium and 8% nickel. Stainless steel faucets are usually made from 18/8 stainless,

But, some stainless faucets are made from 18/10 stainless, a slightly better grade containing 10% nickel used to make knives, fine cookware, flatware, and restaurant-quality sinks. The added nickel makes the alloy a little harder, able to take a higher polish and, for knives, a sharper edge.

Some less expensive faucets, made primarily in Asia, contain a lower quality stainless. As a buyer, you should always look for a certification that the steel used in the faucet is 304 (18/8 or 18/10) or 316 steel. Just the word "stainless" is not enough.

Less expensive fau­cets are sometimes made from a zinc alloy. The best known is an alloy called ZAMAC (for its metal content: Zinc, Aluminum, Magnesium, And Copper) developed by the New Jersey Zinc Company in 1929. The original use of this "pot metal" was to replace more-expensive brass in applications where the durability of brass was not needed but its corrosion-resistant properties were.

It is commonly used in the manufacture of die-cast objects such as children's toys, model trains, locks, cabinet pulls and knobs, zippers, and plumbing fixtures, including faucets. It is a distinctive metal, dull and gray but can be plated with chrome or another finish metal to make it indistinguishable from a brass faucet.

Most faucets that are made of zinc will say so on the box, sometimes indirectly.

The phrase "all-metal" on the box tells you that parts of the faucet contain at least some zinc. If it's all brass, the box will say "All brass". However, some companies get tricky, such as "all brass body and spout" meaning that the handles are probably zinc. "Brass construction" almost always means some of the parts are zinc, as opposed to "All brass construction". "All brass faucet" is another iffy phrase. It sometimes means that the faucet is all brass but it may also mean that some parts of the faucet are brass but some parts are not.

Another indication is the weight. zinc faucets are considerably lighter than all brass or stainless faucets.

Your water contains dissolved minerals. Among these are magnesium, limestone, iron, silica, and even granite.

When water flows through your faucet some of these minerals are left behind as very hard, rock-like, deposits.

In your bathtub or sink these are known as "limescale" or "mineral deposits" and they are the very devil to get rid of after they have built up for a while and etched into the fixture material.

They behave the same way inside your faucet where you can't get at them or even see them. They grind away at the internal moving parts of your faucet, wearing them down over time. Brass and steel can handle the abuse for years and years without failing, plastic cannot.

We're not picking on plastic. We think that the many plastics available have lots of legitimate uses in construction and remodeling. It's just that no plastic is tough enough to be used in a faucet no matter how pretty it looks

We have found, however, that the best way to check for zinc is to get a peek inside the faucet. This may require one guy to wield a screwdriver and another to distract the store clerk.

Removing the handle for a quick look inside the casting where it joins the stem often tells the tale. If it's gray metal, the casting is zinc, if it's "coppery", it's brass. A glance up the spout may also help reveal the faucet's composition, and does not require any disassembly. A pen-light is helpful here. A dull gray spout is zinc. If it's brown, green, or "brassy", then it's brass.

Zinc and its alloys are not all bad. Ancillary parts such as handles and base plates can be made of a zinc alloy without compromising the quality of a faucet. These parts do not need the strength of brass and zinc can be used to save the cost of the more expensive brass.

But, in the body of a faucet or its spout — any part subject to water pressure for year after year, zinc and zinc alloys are highly suspect.


Not, however, as suspect as plastic.

Plastic faucets do have specialized uses. Two examples are in laboratories and in very saline coastal environments where corrosive chemicals or salt-laden air might damage a metal faucet. They are also common in RVs. Since plastic RV faucets are used only a few weeks or months out of a year, they can last a long time. But, for sustained residential use in a bathroom or kitchen, a plastic faucet is not a good choice.

Other than in parts of a faucet under pressure, however, plastic has a place, (although zinc alloys are a better choice). It can replace expensive brass in baseplates, handles, and other components that are not pressurized, But, it is not a suitable material for the pressurized components of faucets, particularly faucet bodies and spouts.

Plastic has crept into faucet manufacturing as it has so much of the products in our homes. Plastic for housings on ceramic cartridges has become virtually universal, as have plastic spray heads (which are called "wands" in the industry). There is no data on the frequency with which the plastic cartridge housings fail, but anecdotally, while failures do happen, they are not a common occurrence.

Plastic wands are another story. Manufacturers began switching from metal to plastic wands a few years ago for three reasons:

Unfortunately, plastic fails more often than metal wands. But, it has now become almost unavoidable. Even upscale faucet companies like have shited to plastic wands. While the wands have gotten better, they are still not on par with metal wands when it comes to longevity.

If you have a choice – and often you will not have a choice if you are to get the look, features, and price you prefer – opt for a metal wand. (By the way, the cure for a wand that is too hot to hold is to turn down the water temperature. There is nothing in the kitchen that actually needs to be rinsed in scalding water.)


There is one form of plastic that does work and works well in faucets. It is cross-linked polyethylene, commonly known as PEX. PEX has been used with good effect to replace copper water pipes for over 20 years. It is recognized by all national plumbing codes as a suitable material for water channels. It is, in many ways, better than copper because it is a lot less expensive, easier to install, and is much less likely to burst from freezing.

It has only very recently begun to be used in faucets, largely in response to the very low lead requirements of the Safe Drinking Water Act effective in January 2014. Since, brass contains small amounts of lead, one technique for reducing lead in drinking water is to replace the brass parts of a faucet that come in contact with water with something that is not brass. Copper and stainless steel are the most common choices but increasingly faucet companies are using PEX for water channels within the faucet, eliminating traditional brass channels.

Advanced technology faucets such as many  Note 2 faucets have replaced all of the internal faucet waterways with PEX. PEX connects the shut-off valves under the sink directly to the faucet valve and the faucet valve to the water exit point in the spout. The faucet body and spout have nothing to do with water flow, they are just decorative shells disguising the PEX tubing and cartridge valve inside. No water ever touches metal, so no lead can leach into the water.

The result is that leaded brass can be used as the basic material for the faucet instead of the more expensive lead-free brass and the components do not have to be as thick-walled because they are not pressurized. All of this results in substantial cost savings in material costs for the company, and lower prices to you, the ultimate faucet buyer.

Rev. 05/30/21