Hi, I have an old tub from 1972. I saw that tub drains unscrew, so I tried it. Didn't work, so before I try harder and break it, are they supposed unscrew on all tubs, especially old ones? I know it is rusty and probably stuck from years of being in there, but I wanted to be sure it is supposed to come out. Assuming it does come out, do you think a newer drain will fit? Use wd40 to loosen it if it comes out?

Edit: Could I break the tub somehow if that drain is supposed to come out or can I break things trying to?

This is what I have:

 

I doubt you would break the tub but you could certainly break the metal in the middle of the drain. This is the type of wrench I use, along with the longest crescent wrench I have. It's a challenge to keep one hand on the top of the tub wrench (to keep it vertical) while tugging on the crescent wrench. In extreme cases, you need to use both hands on the crescent wrench and a foot on the tub wrench.

And yeah, it's been on there almost 50 years so it's not going to want to come off. I doubt wd40 would help, but if you have access to the fittings below, it wont hurt.

If you DONT have access to the fittings below, I'm not sure I would be changing it. It's possible you will need access below to hook up the new drain, as additional parts may be needed.

 

What kind of other parts?

 

https://www.homedepot.com/p/Eastman-...E&gclsrc=aw.ds

Heating up the old drain spud with a heat gun can often help soften the old plumber's putty and make removal easier. But if your tub is fiberglass or your drain is PVC you would want to be very careful about how much heat you apply so as not to melt anything.

 

In a tub that old the parts of the drain have almost welded themselves together with corrosion. It is not uncommon to have to replace the drain assembly below.

With tubs your age and a drain that looks like that it's 50/50 whether or not the spider in the middle of the basket will break. If it does you can replace all the tub drain stuff. Or, you can carefully chisel out the old basket. If done correctly the drain arm on the bottom side can be re-used so all you have to do is screw in a new basket.

If you do have to replace the drain arm then you will also probably have to replace the whole tub drain bits shown in yellow as it's very difficult to find one part of a 50+ year old set. With a new set you are assured the parts will fit together.

 

Rather than WD 40 you might try a penetrating oil, but I don't think it will help. I believe you need good access under the tub and will have to manually destroy the drain to get it out.