I am replacing my bathroom sink faucet. The supply line is 1/2" and the instructions for the new faucet states that a 1/4" supply line is needed. The current supply line is a grey solid tube and seems to be in good condition. Can I use the same supply line for the new faucet? If so, how do I make this work?

  • 2
    You need a 1/2 inch to 1/4 inch reducer fitting. These are readily available at your big box store. Dec 17, 2013 at 15:12
  • 5
    Answer 2: in place of a basin wrench, you can use a basin wrench.
    – BMitch
    Dec 17, 2013 at 15:59
  • Have you tried connecting using your existing supplies?
    – Ethereal
    Dec 17, 2013 at 18:16
  • 3
    A typical faucet supply is 1/2" to the valve and 3/8" after the valve. 1/4" is is what you'd find with an ice maker supply line. I believe these measurements are all "inside diameter".
    – BMitch
    Dec 17, 2013 at 18:32
  • Pro Tip: Some faucets come with an el cheapo basin wrench in the box. It's not the best tool in the world, but it's typically good enough.
    – Tester101
    Dec 18, 2013 at 11:37

1 Answer 1


I've used channel-locks and crescent wrenches, but a basin wrench will save you some busted knuckles. I think that your 1/2" supply is probably coming out of the wall and is grey Polybutylene pipe? If so, you need a 1/2" PB x 1/4" PB shutoff valve, or an adapter to convert to PEX and then the angle shutoff valve.

If you do indeed have a 1/2" supply to your old faucet (very odd indeed -- are you sure that it isn't just the connecting nut that is 1/2"?), then you can probably replace those with braided supplies of the proper size on each end fairly easily. If you post pics of what is going on we can give you more specific advice.

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