Did I learn something new today?

[07classic]

So I was watching one of the shows on Powerblock this morning, and thay were working on something that required a hole cut in it. It was a piece sheetmetal and thay said it is best to use a step drill to make the hole. Is this true?

I did a search on here and found a few things about step drills but wanted to know if I should go out and buy one or just use my dril bits? Thanks

 

[hofferwood]

Good step drill bits are sweet, if you don't need a "precise" hole.
Just depends on the situation. Thin stuff
JMO
Chuck

 

[Danglerb]

HF makes a cheap set of 3 that goes on sale for about $10 that usually is pretty decent for a step drill.

 

[UncleJoe]

I always thought step drills were for really thin sheet metal. One day while reading on here or a metal working forum someone mentioned using a step drill on some 3/16 angle iron. The next day in the shop I needed a hole in something about 3/16 so I decided to give my HF step drill a try. I was expecting a fail and I was shocked at how well it did the job. It was quick and clean.

I would not use them for a precision hole but if I just need a hole for a fastener this does a very nice job.

 

[larry_g]

I was looking for some correct terminology to prepare this answer and found that the cone shaped bit is a 'unibit' and a step drill is one that is a drill and counterbore in one bit. I learned something. http://www.mfg.mtu.edu/marc/primers/drilling/nomen.html

Any way what I was going to add to this thread is that if the material is not thick enough to allow the straight part of the flutes to enter the hole before the tip brakes through the other side then your going to have problems.

lg
no neat sig line

 

[amolaver]

HF makes a cheap set of 3 that goes on sale for about $10 that usually is pretty decent for a step drill.

i just put aerocatch hood pins / latches in a car yesterday and used the 'fattest' HF step bit to drill the initial holes in the hood for locating where the pins come through. bit worked great, no complaints. i punched the starting point, but was still surprised the bit didn't want to walk at all.

no doubt there are better ones out there, but it got the job done.

ahm

 

[Brad54]

I've been pleasantly surprised by my HF step drills. After reading several posts here saying they were good, I get a set.

-Brad

 

[bmxr4life87]

They are great for sheetmetal but can be used on thicker stuff within reason... The bigger ones are great because you can make fairly large holes without having to have larger drill bits

 

[amorrow]

I first used a step bit to drill through my '65 Mustang firewall to run the line for my oil temp gauge. They make for smooth drilling in sheetmetal, and it's nice using one bit to get the job done, especially when working in tighter areas such as an engine bay.

 

[OccupantRJ]

Unibits come in a few different sizes and styles, and the length of cut for each diameter will vary according to which bit you end up with. My largest one is 1-3/8"