Photos of my toilet water supply line, which is the part below the valve:

Based on the appearance, it only fits the description of galvanized iron (which is apparently the same as galvanized steel). However, based on numerous sources, galvanized steel has been mostly phased out in the 1960s, but my house was built in the 1990s (in Toronto, Ontario, Canada, if that matters).

I want to cut this pipe in order to install a quarter-turn valve with compression connections, but I am unable to find any close quarters tubing cutters that can cut galvanized iron/steel.

So my questions are:

  1. What material might the toilet water supply line be?
  2. Should I attempt to cut a galvanized iron/steel line with a cutter that is meant for everything but iron/steel (E.g. The Ridgid 40617 cutter states it is for "hard and soft copper, aluminum, brass and plastic tubing", but doesn't state iron/steel)?

Update 1 So, I scraped the back of the tubing with a file as one user suggested as shown here, and it appears to be copper. Also, a neodymium magnet was not attracted to it, as another user suggested in trying to do so.

  • See if a magnet is attracted to it. What is the (outside) diameter? Jan 15, 2017 at 13:39
  • @JimStewart The outside diameter is 5/8". I updated my post to show the scratched surface of the tubing. I used a neodymium magnet on it, which had no attraction. Just for my knowledge, what material does it suggest if a magnet was indeed attracted to it? Apparently, steel may or may not attract magnets, depending if it has nicklel in it, right? Jan 19, 2017 at 22:51

3 Answers 3


That is either a painted or plated 1/2" copper line. If it is plated, the plating is failing or failed. Either way take a strip of emery cloth and clean it up before adding the compression fitting

  • 2
    I agree, that looks like 1/2" copper pipe that someone has painted with silver paint. Jan 15, 2017 at 13:14
  • I also pictured the plumber gave it a solder coat to color it, note the little spatter on the escution, it looks like unfluxed soldering that fell on the surface... I don't see a solder joint and I don't think it is one of the toilet stops that come with a chromed copper supply the connects below the floor.
    – Jack
    Jan 15, 2017 at 17:08
  • I thought that was splatter too until I blew up the photo close, looks like lint/dust that got in the way of some chrome spray paint. Jan 15, 2017 at 21:23
  • @Jack The patch was just some dust left behind by my tissue paper that I used to clean it up before snapping the photos. I don't have emery cloth. Can I use a steel wool or sandpaper in its place? Do I have to clean it until the orange colored copper is revealed? Jan 19, 2017 at 23:00

It looks like copper with blue green patina, the result of ordinary oxidation, hiding the characteristic orange color of fresh copper. If you are uncertain, scratch the surface with something like sandpaper, steel wool, file etc. You will most likely see the same color as newly minted pennies.

If you see copper, your question number 2 is of no concern. If it does not show copper, then you can always use a hacksaw or a jigsaw with a metal cutting blade to cut the pipe. Of course, no matter how you cut the pipe, make certain that the water is turned off up-stream.

  • Indeed it does appear to have an orange color after scratching the surface with a file, as shown here. Thanks! Jan 19, 2017 at 22:46

If you cut the pipe, you will have solder or shark bite a replacement. Are you sure it's not just threaded onto the pipe? Hex sides on the valve are a small give away that it could just be a threaded pipe and valve.

  • ...No. The hex on the valve is so you can connect the fitting on the top without torquing the pipe connection below. If you "try to unscrew" a soldered joint, you'll twist/flatten the pipe, and then you'll have to rip the floor open to get to the next joint - bad plan. If it was threaded pipe, you would see pipe threads below the valve.
    – Ecnerwal
    Jan 15, 2017 at 21:11
  • The more I looked at the picture, it did look soldered, but in regards to "seeing threads", none of my pipes have visible threads, but then again, most of mine are now pcv, cvpc or pex.
    – Jeff Cates
    Jan 20, 2017 at 21:36
  • @JeffCates Yeah I don't think it's a threaded pipe. I tried twisting it lightly and it did not turn one bit. Is a compression fitting not also an option if I cut the pipe? Jan 27, 2017 at 0:19
  • I'm not sure I would trust a compression fitting for that, but a shark bite would work. I used them in several places on the 2 remodels I did. Similar to compression, but you push it on right and it locks in place.
    – Jeff Cates
    Jan 27, 2017 at 14:16

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