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.
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.
A Rose May Be Always a Rose but a Faucet is Not Always a Faucet
There is almost no language more confusing than Plumber. 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 usually 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.
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 an alloy of copper and zinc with small amounts of other metals — the most troublesome being lead (added to make brass more malleable and easier to form). It is also very dangerous to health, and a great effort has been made to get lead out of faucets and other plumbing components over the last 40 years. Today any but the smallest amount of lead is forbidden by law. Its replacement is bismuth which has no known adverse health effects.
Aluminum may be added to make the brass stronger and more corrosion resistant — the so-called admiralty or naval brasses used in salt-rich maritime environments contain a relatively high proportion of aluminum.
Tin may be added to combat a process known as dezincification in which the brass loses its zinc over time when exposed to water, making the remaining brass brittle and porous.
The copper in brass is anti-microbial — it kills germs — although no one yet understands exactly how the process works. What we do know is that 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.
Brass is prized for faucets because it is very resistant to corrosion, has a relatively low melting point — making it easy to cast — is soft enough to machine with little effort yet hardy enough to endure the rigors of life as a faucet, takes finishes such as chrome plating very well, and is easily recycled. About 80% of the brass used in new faucets was previously used to make something else.
The brass used in faucets today is not the same brass of yesteryear. Lead, commonly added to brass to make it more malleable, is now virtually banned in faucets and most other plumbing fittings and fixtures. 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%). To comply with the new restrictions on lead, today's faucet brass is "lead-free" brass that uses other additives for malleability.
The other upscale 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.
Stainless Steel Faucet
Photo: Moen, Inc.
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 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.
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, and able to take a higher polish.
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.
Photo: Kingston Brass
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 an all-brass faucet.
Most faucets that are made of ZAMAK will say so on the box, sometimes indirectly.
Why is Plastic a Problem?
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
The phrase "all-metal" on the box tells you that parts of the faucet contain at least some zinc. If its all brass, the box will say "All brass". However, some companies get tricky, such as "all brass body and spout" means 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 ify phrase. It sometimes means that the faucet is all brass but it may also mean that the body of the faucet is brass but some parts are not.
Another indication is the weight. ZAMAK faucets are considerably lighter than all brass or stainless faucets.
We have found, however, that the best way to check for ZAMAK 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 ZAMAK, if its "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 ZAMAK. If it's brown, green or "brassy", then it's brass.
Zinc and zinc 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 ZAMAK are highly suspect.
Not, however, as suspect as plastic.
We have never seen advice from a responsible source on the purchase of a plastic faucet other than some variation of "Run, run away, fast and far."
That is also our advice. Plastic is not a suitable material for faucets, particularly faucet bodies and spouts. It is simply not durable enough for a faucet. And, there is no reason to buy a plastic faucet when for a very few dollars more you can always find a suitable metal faucet — maybe not all brass but at least ZAMAK, which is a giant step up from plastic.
But, there is at least 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 and 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 probably the best choices but increasingly faucet companies are using PEX for water channels within the faucet, replacing the traditional brass channels.
Advanced technology faucets such as many Delta and Brizo 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.