# Hole saw size



## HARRY304E

sp009 said:


> After 3 months of heavy use and abuse my harbor freight uni-bit/ step drill is getting dull. Was thinking about switching to hole saws but was wondering what sizes you all use the most? Was thinking about just getting a kit but, only really used my step drill for 1/2 inch ko's mc connectors.


Just buy another unibit and use some cutting oil when drilling it will last much longer...:thumbup:


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## Lone Crapshooter

I use 7/8 for 1/2 inch, 1 1/8 for 3/4 and 1 3/8 for 1" I use the Lennox carbide tipped hole saws. They seem to do a good job in carbon steel. 
I will borrow the Ideal saws from work if I am working with stainless. I was told that the Ideals will cut 600 holes in stainless with out coolant. Don't know if that is true but they do a good job on stainless.

LC


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## Dennis Alwon

Rule of thumb is add 3/8" to the pipe size you want. Thus a 1" emt needs a 1 3/8" hole, etc


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## RIVETER

Lone Crapshooter said:


> I use 7/8 for 1/2 inch, 1 1/8 for 3/4 and 1 3/8 for 1" I use the Lennox carbide tipped hole saws. They seem to do a good job in carbon steel.
> I will borrow the Ideal saws from work if I am working with stainless. I was told that the Ideals will cut 600 holes in stainless with out coolant. Don't know if that is true but they do a good job on stainless.
> 
> LC


For what it's worth when I am cutting stainless I stuff the hole saw with a rag and soak it with cutting oil. As it spins it applies the oil to the teeth.


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## A Little Short

Dennis Alwon said:


> Rule of thumb is add 3/8" to the pipe size you want. Thus a 1" emt needs a 1 3/8" hole, etc


Irwin makes a unibit for knockouts. They are marked for the size knockout needed. For a 1/2" you use a 7/8" and for a 3/4" you use a 1-1/8".


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## jwjrw

The greenlee 7/8" and 1 3/8" are freaking awesome.


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## MDShunk

I got a set of the Lennox carbide hole saws for knockouts. They are freaking awesome! They are very shallow hole saws, with a spring that ejects the slug. I got them specially for a buttload of stainless work, and they're still going strong. I highly recommend them. I have a whole kit of stainless knockout punches, but I've been using the Lennox carbide knockout holesaws for knockouts up to 1-1/4", and only punching stuff that is bigger. 

If I was to only buy one holesaw, it would be a 7/8", because that's the size you need to get the drawstud in for the bigger knockout punches.


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## jwjrw

MDShunk said:


> I got a set of the Lennox carbide hole saws for knockouts. They are freaking awesome! They are very shallow hole saws, with a spring that ejects the slug. I got them specially for a buttload of stainless work, and they're still going strong. I highly recommend them. I have a whole kit of stainless knockout punches, but I've been using the Lennox carbide knockout holesaws for knockouts up to 1-1/4", and only punching stuff that is bigger.
> 
> If I was to only buy one holesaw, it would be a 7/8", because that's the size you need to get the drawstud in for the bigger knockout punches.


Ideal has the same thing


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## oww-is-that-hot?

jwjrw said:


> Ideal has the same thing


Ideal _and_ Klein have the same thing. I'm pretty sure they are exactly the same though, awesome. I have Ideal. Gotta be willing to fork over some extra $ though, but you get more holes IMO


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## MechanicalDVR

I would get the unibit for 1/2" & 3/4" ko's and a hone to keep it going.


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## don_resqcapt19

I use the Blair holecutters for 1/2 through 1" conduit. I have not tried their carbide tip version, but am very pleased with how the standard ones cut and last. The key is high drilling pressure and low RPMs. We would normally use Extra Thick Tap Magic as the cutting fluid, especially if drilling stainless boxes.


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## MarkyMark

The carbide hole saws are the shiznit for 1" + holes. For 1/2" and 3/4 holes, I think a sharp uni-bit is just as quick if not quicker than a hole saw, and to me makes a cleaner hole. Around here, Harbor Freight step bits cost somewhere in the 3 for $14 range. When they get dull, I throw them out and buy new ones.


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## oww-is-that-hot?

MarkyMark said:


> The carbide hole saws are the shiznit for 1" + holes. For 1/2" and 3/4 holes, I think a sharp uni-bit is just as quick if not quicker than a hole saw, and to me makes a cleaner hole. Around here, Harbor Freight step bits cost somewhere in the 3 for $14 range. When they get dull, I throw them out and buy new ones.


oh, that's what I forgot to say about the carbide hole saws, their holes are C-L-E-A-N
It's seriously like using a punch, and It's at least twice as fast as a unibit. That goes for 1/2", 3/4", and 1". 
They're totally different than regular hole saws and don't require oil in the slightest.
At least not that I can tell.


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