Drilling Metal

[Mr.GfC]

I'm an Disabled American VET living in Lima Peru. Just got ito welding out of necessity for a workshop I'm building. [https://freeimage.host/mrgfc/?list=i...3&seek=Kpl1oP]

I have watched video after video on building stuff... welding, bolting, and drilling. I see people drilling holes with these:

all day long like a hot knife through butter. Can anyone link me a website that sells a good set of these, please. The set I found here dulled after the first use.

Regards,
Mr.C

[smithdoor]

You can reshaping that type of cutter.
It is a sheet metal drill typical found at AC suppliers and electronics suppliers.

Dave

I'm an Disabled American VET living in Lima Peru. Just got ito welding out of necessity for a workshop I'm building. [https://freeimage.host/mrgfc/?list=i...3&seek=Kpl1oP]

I have watched video after video on building stuff... welding, bolting, and drilling. I see people drilling holes with these:

all day long like a hot knife through butter. Can anyone link me a website that sells a good set of these, please. The set I found here dulled after the first use.

Regards,
Mr.C

[Mr.GfC]

Um, I know you've been a member for a long time and have lots of posts, but I have to disagree with you that this bit is just for sheet metal.
Here is a link to a that shows what I mentioned before "I have watched video after video on building stuff... welding, bolting, and drilling. I see people drilling holes with these all day long like a hot knife through butter. "

[jrporter]

Not just for sheet metal - they are great when you want a tapered, stepped hole in thick metal..
Joking aside, they are also called unibits - check out the section on them in the drill bit wiki. Mostly for sheet stock in gauges thinner than the width/length of the steps
https://en.wikipedia.org/wiki/Drill_bit#Step_drill_bits

[jpump5]

Those Unibits are best used in fairly thin material
because each step on the bit is short. I like them
for drilling in electrical panels because with only
one Unibit and a set of knockout punches,I can
make any size hole I need up to 2”. ( I don’t really
like using hole saws in steel).What I don’t like about
them is the cost and the fact that when the tip
dulls, the whole bit is useless, unless you use
a twist drill to start the hole. They also have a
tendency to grab when one step breaks through
and the next one starts. They cut pretty fast, but
I don’t know if I’d say “like a hot knife through
butter”.

[wb4rt]

Go slow and use oil. As said, best on thinner stock 11 gauge max (in my opinion, not trying to start an argument).

From another old vet.

[Lis2323]

Unibit step drills will bore through thicker (10 gauge + ) steel like a hot knife through butter ... until it doesn't. LOL


Sent from my iPhone using Tapatalk

[smithdoor]

Use screw machine drill bit for 18 gauge and up.
Easy to to re-sharpen I would buy this type by the gross to keep the cost down.

I would start with 3/16" pilot hole then drill up to 11/16" hole size.

Dave

Um, I know you've been a member for a long time and have lots of posts, but I have to disagree with you that this bit is just for sheet metal.
Here is a link to a that shows what I mentioned before "I have watched video after video on building stuff... welding, bolting, and drilling. I see people drilling holes with these all day long like a hot knife through butter. "

[danielplace]

Uni-bits are for sheet metal cabinets mainly as they were originally designed but then the Chinese saw the value in making them a house hold item.

They can be used in what ever you want to use them in. Obviously if you like the results for what your doing by all means but they were meant for sheet metal.

To get any of them worth owning you have to pay the price for a good one. Most run of the mill Ebay Amazon cheap junk it going to be pretty worthless unless all you work with is plastic and even then it will never function like a quality piece will.

Plan to pay something like $50-$90 or thereabouts depending on the size your looking for.

I own several high quality cobalt ones from Irwin and Greenlee but for me personally I almost despise them. They just suck for most everything IMO.

I prefer to use the Greenlee hydraulic knockout punch when I want clean accurate holes in sheet metal cabinets or whatever it is. If it is smaller holes use a regular bit and if it odd size or whatever I use a hole saw.

Holes saws I have ever bit in every arbor I have replaced with hardened steel rod NOT a drill bit. That way you use a drill bit separate in the drill to make pilot that way the rod holds the holes saw true while you making the hole. A drill bit pilot bit just wallers out the hole and can't keep hole saw on track.

[danielplace]

Damn that was a little hard to read. Sorry guy's was in a hurry and didn't proof read. Lots of mistakes and can't edit nothing.

[smithdoor]

It is happens to me.
If on computer it does happen but smart phone it not so smart.
I forget to prof read all time and with autocorrect and big fingers on the smart phone 📱 look out.

Dave

Damn that was a little hard to read. Sorry guy's was in a hurry and didn't proof read. Lots of mistakes and can't edit nothing.

[INXS2]

Smithdoor (Dave), I understand where your coming from about the big fingers (I have the same problem) but the way you string sentences together sometimes makes no sense and are hard to interpret. Sorry, just an observation.