What size hole saw do I need for 3/4" pipe?

[chad22]

I've probably already answered my own question.

I'm kinda stuck on this. I'm needing to drill a hole to insert a 3/4" pipe to use as a bushing. What size of hole saw do I need to make this hole?

If my math is correct I'm thinking 1-1/2" is the size of hole saw I would need so the outer diameter of the pipe will insert into the hole? I just want to make sure I buy the right size hole saw.

Forgive me. I was staring at the pretty girls in school instead of my math book. So math isn't exactly my forte. :laughing:

Thanks

Chad

 

[brandoro]

1-1/8" hole saw is used for 3/4" electrical conduit. What kind of pipe are you using?

 

[k0ua]

It is a hard question. I am going to make some assumtions.
steel pipe sch 40. nominal should be about 1.050 inches. so use 1 inch hole saw if sawing in wood, then ream/sand as neccessary if you want an interference fit, if you just want a big hole it will fit into then maybe 1 1/8 or 1 1/4 would be fine. I will never forget the 2 girls that sat behind my row in math class. I needed to turn around a lot and check on them:laughing::laughing:

James K0UA

 

[chad22]

I'm using 3/4" galvanized water pipe. I used 1" hole saw and it was too small.

 

[k0ua]

Then my 1.050 should be pretty accurate, put your dial calipers on it and find out... If you dont have any, you should get some, they are about 12 bucks. and then you will always know how big something is from 0 to 6 inches..:thumbsup: Harbor freight ones will be ok.. or any machine tools store. if you want good ones. There are just certain things a man should own in this world, and an inexpensive set of 6 inch dial calipers are one of them.

James K0UA

 

[Jw5875]

Hope this helps!


Pipe Chart

JW5857

 

[k0ua]

yes it should be 50/1000 too small, thats why I said ream/sand to get and interference fit, if you use the next size up 1 1/8 it will be to large, at 1.125, and I understood you wanted to use this as a bushing..?

James K0UA

 

[k0ua]

you should be able to ream a piece of wood with the 1 inch hole saw by running the hole saw back and forth while "wiggleing" the hole saw some in the hole to "ream it out some. in other words make the hole a little larger by 25/1000 on each edge, for the total of 50/1000 of an inch you need for a tight fit in the wood..if that is what you are looking for. if you just want the steel pipe to fit through the hole then 1 1/8 or 1.125 is what you want, but it will be a very sloppy fit.

James K0UA

 

[k0ua]

By the way, maybe if you told us what you are building, we could reply better, I assumed you wanted a tight fit of the pipe in the wood, since you mentioned bushing. you may be able to just drive the 3/4 pipe into the 1 inch hole, if the wood you are using is strong enough, by greasing the pipe and hit the end of the pipe with a hammer.

James K0UA

 

[chad22]

This is for my backhoe I'm building.

I want to stick the pipe through a piece of steel square tubing, weld it in there and put a bolt through the pipe. So I guess if the hole is a tiny bit big I can weld around it.

I might be able to force the pipe through the 1" hole but doubt it.

I have another question. Which is bigger and which is smaller?

The 1-1/4" hole saw, the 1-1/8" hole saw?

Chad