Cutting sheet metal

[Wes85L]

I want to cut some circles in sheet metal for gauges I have but am not sure how to go about it. What tool works best for this? Also how can I cut a square or rectangle accurately? I do have a dremel but don't have great control using it. The cut off wheel always jumps around on me. Thanks

[BadAssPerformance]

Depends on teh size holes, but for circles in sheet metal, the best tool is a screw type hold punch like electricians use to pierce holes in electrical boxes.

If it is aluminum another way to get both round and square holes is to use a coping saw. Just need to drill a hole to put the blade thru to start the cut.

[dodge78]

Hole saws work well if you find the right size.

Hole punches work great but can be expensive. If you find a deal on a good brand they are worth the money. Some hole punches are square and recangular, also.

[RoadWarrior222]

Hand nibblers work good for larger holes. Well depends on the type, the type that cut a strip out you probably don't want to use for anything smaller than 2" the ones that punch a piece out are easier for smaller and funny shape holes. IF you have a sabre saw you can get metal blades for it for thin metal, those are easier to keep in line for straight cuts and okay for wide curves. Not good for small pieces though, 'coz you need room to clamp it down.

You might have more luck with the dremel if you clamp the work down firm and flat, use two hands and have some bench to brace your arms against so you can move it with wrist movement.

Hole saws can be used carefully too, just use them against scrap wood, and throw lots of oil on.

[Wes85L]

I went to the hardware store today and bought a 2 1/16" hole saw and a coping saw. I also bought a sheet of .064 4x10 aluminum. I am installing 2 1/16" gauges on the dash in a panel. I think these tools along with the dremel will be enough for the gauges and other accessories round or not that I may add. I don't have a workbench or anything to clamp with so keeping the sheet from moving might be a pita. I suppose a drill press would come in handy for this type of work.

Hmm...I just noticed the hole saw I bought doesn't have a drill bit in its center. None of the others I saw there had one, so does it even matter? Is its purpose to keep the hole saw from moving around on you?

[BadAssPerformance]

yes, the drill bit in the center is so that the hole saw does not skate all over the surface of the metal.

[Tony Lane]

Why not use a pair of aircraft shears? That's what all the tinners use at work...

Get ones that cut circles, depending if you want to go right or left, red handled ones go to the left, and green handled ones go to the right. Yellow or orange are straight snips.

A hole saw will give you a perfect circle, not sure how well they go through sheet metal. Depends on the gauge I guess.

[Wes85L]

The hole saw is bi-metal and says to use on any machinable material. I noticed also it has a set screw so I think I can attach a regular drill bit to make a pilot hole.

Thanks for the help guys. I got the info I needed.

Btw JT, the fabrication work on your website is top notch! Is the speed shop still operating?

[dodgeboy77]

Aviation snips won't work for the relatively small holes that he's trying to cut. The hole saw should do the trick.

Wes - usually you need a 1/4" bit for your pilot drill. To keep your holes where you want them, first drill a smaller pilot hole exactly where you want the center of the hole, then enlarge to 1/4". If you want to be extra accurate, then put a piece of 1/4 steel rod in the hole saw instead of the drill. Sometimes the pilot drill will start enlarging the pilot hole as you are cutting, making your hole off-center. You were lucky to find a 2 1/16" hole saw. That's just right for the gauges. Usually they go from 2" to 2 1/8".

Another tip- if you clamp your aluminum to a scrap board it will keep it steady and give you a better cut as the hole saw goes through the aluminum that is supported by the wood. Good luck, Bill

[Wes85L]

Aviation snips won't work for the relatively small holes that he's trying to cut. The hole saw should do the trick.

Yeah, I have them and they are too large and they made the metal edge jagged and bent.

You were lucky to find a 2 1/16" hole saw. That's just right for the gauges. Usually they go from 2" to 2 1/8".

Yeah, I had checked online beforehand and didn't find any in that size. I can't figure out why it didn't come with a pilot bit though. Aren't they usually a part of the hole saw, not removable?

[RoadWarrior222]

Yeah, I had checked online beforehand and didn't find any in that size. I can't figure out why it didn't come with a pilot bit though. Aren't they usually a part of the hole saw, not removable?

Usually if you buy a set they come with the drill bit and mandrel, but don't remember seeing single ones sold like that, unless they're a kit for drilling lock holes in doors.

[guyd_15]

Hole saws generally use a special pilot bit. It's just a drill bit that has a flat area gound on the shank so that allen screw you noticed will keep the bit tight.

Tips:
Center punch the material, that way the pilot bit won't walk
Secure the material your drilling, use both hands to steady the drill
Keep the hole saw square to the material

Guy

[dodgeboy77]

Wes - What brand is that 2 1/16" hole saw and where did you get it?

Bill

[Wes85L]

2-1/16" hole saw

http://doitbest.com/Main.aspx?PageId=64&SKU=336256

Here is the pilot drill I couldn't find earlier

http://doitbest.com/Hole+Saws-M.+K.+...sku-336853.dib

CRC cutting oil

http://www.nolansupply.com/lg.asp?imgnumber=22214050

[dodgeboy77]

Cuts tool steel and stainless! Nice unit - I want one! Bill

[RoadWarrior222]

Cuts tool steel and stainless!

I might have to get one, got some peices of stainless I'm gonna want holes in. Was gonna take it realllllllll easy with a powered fretsaw.

Wonder if it will cut into stainless tube okay..... thinking stainless log intake....

[dodgeboy77]

If anyone is interested, I spotted one on eBay:
http://cgi.ebay.com/2-1-16-MORSE-BI-...QQcmdZViewItem

[MiniMopar]

I use hole saws to cut blow holes in computer cases all the time. I bought the expensive one and it seems to last forever. Just be patient and go slow. If you are cutting steel, some cutting oil helps things along and keeps from bogging the drill. If drilling by hand, the hole will be a little larger than it should be as the hole from the pilot "wears out". On a drill press they make nice, clean holes.

[Wes85L]

Yeah, the drill press is next on my list of tools to get. I bought a riveter and jigsaw yesterday and got the pilot drill that attaches to the hole saw. I haven't even started cutting anything for the gauges. I'm doing so many other things with this car almost every day.

[dodgeboy77]

<<I'm doing so many other things with this car almost every day.>>

Welcome to the world of TD's!!