Step Drills 2

[rlee53]

Building a small enclosure. Looking for a low cost method for occasional use to put holes in 14 Ga sheetmetal box. Do the step drills work O.K.? I have some hole saws, but not in every size I need.

The punches are nice but are little over my budget right now.

 

[ScottyUK]

They're ok - run them at a fairly slow speed and use a cutting compound or fluid. A pedestal drill is better than a hand-held, mainly because hand-helds are usually too fast to get decent tool life even on their low speed. Don't use step drills on stainless steel: they will be blunt in no time flat. If you must drill stainless use carbide tipped holesaws, or put the money toward a press tool or punch (or send it to your local panel shop and let them worry about it).

BTW, why on earth is this in the PLC forum?



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If we learn from our mistakes I'm getting a great education!

 

[rlee53]

Sorry for the wrong forum; I figured you guys would have plenty of experience with all the ways for making holes in enclosures.

 

[HCBFlash]

It caught my eye! Still, I don't really know what other forum in particular you'd go to.

as you go thicker than 14 ga you'll have more reason to use holesaws.

Torque can damage you, your drill motor, your workpiece, and your drill bit,,,, and step drills need all the torque you can get them. Scotty's right about using a drill press (pedestal drill) for speed reasons as well. Unfortunately I'm not enough of a toolmaker/machinist to be able to quickly tell you a good surface speed figure, or quickly explain how that works, but I'll make a suggestion. Metal cutting holesaws come packaged with information sheets, which give speeds (RPM) for use in various materials (Aluminum, steel, and SS are each VERY VERY different). Find one of those sheets and use the value given for whatever size your hole will be. A step drill is simply a "1 or 2 toothed holesaw", so it should turn at the same speed.

I've worked with dozens of "tradesmen" that still can't figure that out, so I'll leave it at that.

 

[rlee53]

I picked up a step drill yesterday and it worked very well. Lot's of chips though. Made a mess, since all the material from the hole gets cut into chips. One of these days I'll invest in the punch tools, but this is good enough for now. Thanks guys.

 

[mchenney]

These are step drills or unibits:

http://www.tradetufftools.com/index...Path=217_336&gclid=CN6pwdaW448CFRGCGgod6lUzCQ

Great for non critical sized panel work, best used in a drill press w/ depth setting as to be safe.

Greenlee punch set for consistant results for standard panel hole sizes and adding holes in the field.


Dennis McHenney
mchenney@mindspring.com

 

[panelman]

get a greenlee (or similar) set.

Ebay is your friend