drilling 4 1/2 inch hole in metal panel

[MAC702]

A hole saw can make a good clean hole but it has to be drilled straight, good saw and good bit. A slightly crooked bit is all it takes to ruin it.

And yet making the bit slightly crooked makes it cut the hole a lot faster, so it depends on the job as to which you want.

 

[ritelec]

The magical impact drill will do the job ? Just make sure it's on the proper torque value.

 

[jmellc]

Funny, my vices follow me wherever I go.
I sometimes don't have a vise when I need one.

I always have my vices, whether I want them or not.

 

[Coppersmith]

All these discussions of accidents with drills is giving me the willies.

When I was a 1st year apprentice, another 1st year using a macho drill broke his arm when it spun and spent the rest of the job handing out material from the trailer. I learned drills can be dangerous and have been very cautious around them every since. Sometimes I will hire a core drilling company rather than do it myself.

 

[mlnk]

Last time I drilled a 3.5 inch hole in metal I flooded the hole saw with water and drilled with a battery drill. It took a while but bit still looks new.

 

[JFletcher]

I have a ton of drill stories, none of which have happy endings. Closest I ever came to breaking something on me was driving a lag bolt through a band board
No torque clutch, no speed control (stupid, I know), the bolt bound up, and the drill spun out of my hands, trigger lock got engaged, it wrapped up the drill cord and about 30 foot of extension cord on itself before it yanked the cord out of the receptacle.

Have also had a Roto Hammer with a masonry bit on it catch the side of a piece of rebar, flip me upside down and pin me to the ground.

I am not superstitious, however when it comes to drills, I believe that there is a Murphy.

One of my first jobs, I had to drill through a block wall to run some comcables. I checked the other side of the wall for obstructions, all appears good. I start drilling, of course it is quite loud. About halfway through the hole, I hear a faint sound over the drill. I power down the drill only to realize the building's fire alarm system is going off. Withdrawing the drill bit from the hole, and shining the light inside of it, I see a whole bunch of mangled copper. I hit a pull station PVC conduit in the block.

 

[Coppersmith]

Withdrawing the drill bit from the hole, and shining the light inside of it, I see a whole bunch of mangled copper. I hit a pull station PVC conduit in the block.

This reminds me: again when I was a 1st year apprentice, same job as the other incident. My J-man is drilling a block wall while standing several steps above me on a ladder. I'm standing near his feet holding the ladder. All of a sudden I hear him scream and I feel liquid hitting me. For a moment I thought the drill had spun and ripped an arm off and blood was spewing all over me. Turns out he merely hit a water line.

 

[jmellc]

And yet making the bit slightly crooked makes it cut the hole a lot faster, so it depends on the job as to which you want.

No, I mean a bit that is crooked, twisted, damaged. I know you can tilt slightly and make cutting faster. It can let the saw go too far in every direction and distort the hole.

 

[Stevenfyeager]

A punch would be great. A hole saw would be just fine, too. Half the job of being an electrician is drilling holes. It's what we do.

Jig saw?? No way.

A punch ? My hole has to be 4 1/2 " diameter. (what my 4 " PVC threaded adapter measures) What brand or website would sell this size punch? Is it a device wtih a rachet like my Green Lee 2 " kit?
Thank you.

 

[Stevenfyeager]

A punch ? My hole has to be 4 1/2 " diameter. (what my 4 " PVC threaded adapter measures) What brand or website would sell this size punch? Is it a device wtih a rachet like my Green Lee 2 " kit?
Thank you.

In that same CT panel, we had to drill 2 " holes. my 3/4 to 2 " Green Lee kit was almost more than it could handle. We had to use a 24 " pipe over the ratchet to have enough leverage to cut through that thick steel, but it worked.

 

[Besoeker]

Good grief!
Fifty posts on drilling a hole in a panel!
For twelve quid you can get a 115mm hole saw. Job done.

 

[Besoeker]

This will do nicely:

 

[MAC702]

Has the OP objected to the relevant conversation, caveats, and tangents?

I saw it mentioned, so I'll second the reminder that a wet towel stuck up inside the hole saw while using it keeps it cool and it will last a lot longer. Water isn't as good as oil for a cutting fluid but it's a lot better than nothing and is relatively free and a lot easier to clean up.

Another trip is to drill a few relief holes on the perimeter to give your teeth space to clear chips easily.

 

[Besoeker]

Has the OP objected to the relevant conversation, caveats, and tangents?

Nope. Nor am I.

 

[growler]

I am in the buy a punch camp. If not borrow one. Rent one. Take another EC to lunch for one. Check your local apprenticeship program.

For twelve quid you can get a 115mm hole saw. Job done.

I'm not sure they accept quid here. By the way. Vats a Quid?

I actually know what a quid is and I agree that you can buy a hole saw cheap enough and it's really no big deal.

Years ago I had to cut holes that big in bulk storage tanks filled with gasoline and no one was hurt (that's like 1/2 boiler plate). Had to be careful of sparks so we used pneumatic drill and kept water on the saw while drilling.

 

[Besoeker]

I'm not sure they accept quid here. By the way. Vats a Quid?

I actually know what a quid is and I agree that you can buy a hole saw cheap enough and it's really no big deal.

Years ago I had to cut holes that big in bulk storage tanks filled with gasoline and no one was hurt (that's like 1/2 boiler plate). Had to be careful of sparks so we used pneumatic drill and kept water on the saw while drilling.

Tough job compared to puting holes in a 2mm or 3mm electrical panel.

On the quid thing, we use different slang words here. Differs greatly even within the UK.
Nobody from south of Hadrian's wall would understand the term "sauchlie wee bauchle"........

 

[Coppersmith]

Good grief! Fifty posts on drilling a hole in a panel!

Isn't that the beauty and essence of this forum? We deep dive into subjects to get authoritative answers to mundane questions.

 

[Besoeker]

Isn't that the beauty and essence of this forum? We deep dive into subjects to get authoritative answers to mundane questions.

Or any internet forum.

 

[Fulthrotl]

That’s why you drill the pilot hole first without the hole saw attached

i use a piece of 1/4' drill rod instead of a pilot bit,
drill the pilot hole first.. then the pilot doesn't egg
out the hole and make the hole saw become a
migratory animal.

with a 12" long piece of drill rod, you can drill a 4 1/2" hole
thru the slope on robertson decking, plumb. go nice and slow,
and it will work fine.

 

[drcampbell]

... Nobody from south of Hadrian's wall would understand the term "sauchlie wee bauchle".

Nor west of Lochboisdale, absent some sort of artificial affinity, family connection, or hospitalization in a serious Burns unit.
https://www.electricscotland.com/humour/h65.htm