Drilling metal with hand drill?

[Doug4d3s]

I resorted to using a hand drill to make some holes in a 1/4"-thick piece of steel plate (for a work table I am building). I got the first three holes drilled using the mill, but gave up trying to align the 2' x 4' piece of steel under the mill's spindle.

The hand drill has a couple problems here--one that the hole is not perpendicular, and the other is that the drill tends to wander off the intended location.

In this particular instance the holes not being perpendicular is not so major a problem, but the drill wandering off-point is.

Using a regular hand drill, is there any way to help either of these problems? I have tried lots of different 2-flute twist drills over the years, and while the split-point drills work somewhat better, they still leave a lot to be desired. I have heard people say that the single-flute step drills are great for cutting holes in sheet metal, but I've not ever heard of anything really meant for drilling <.5" holes in thicker (1/4"-1") steel plate.
~

[PeteM]

Center punch and spot drill your hole to start. That will keep it from wandering, especially with larger sizes.

You can make up a drill bushing out of a piece of scrap.

There are also various cheap alignment jigs for portable electric drills that will keep you within a degree or so of square -- some will also adjust to angles. They attach by unscrewing your check, screwing your drill on to the jig, and replacing your chuck on the jig. Portable drills are cheap -- I keep one attached to an alignment jig for the times it's needed.

Some drills also have cheap alignment levels on them to keep you within a few degrees of plumb and level. It's easy to see in one plane if your leveling, but harder in the other. If you don't have a jig, don't want to make a bushing, nd don't have levels on your drill, then consider clamping a square to your work as a guide.

[Russ Hanscom]

Depending on the final size hole you are looking for, drill in several sizes. I typically start with a 3/16 bit, since I have a bunch, then to 3/8, and so forth. Mark with a centerpunch. Multiple hole sizes also makes it easier on the hand drill - and operator!

[JimGlass]

I have drilled & tapped hundreds of holes with a 1/2", 12V DeWalt Cordless drill. Secret is mostly practice, practice, practice.

To drill a square hole, I eye ball the drill square then check again 90 degrees to the first check. I place one hand on the hand drill grip and the other right behind the spindle then push the drill striaight in. Ususally works pretty well.

Sometimes it helps to grind more clearance angle on the drill point. This reduces down feed presure but sometimes the drill will dull faster.


Center punch and center drilling helps to establish the correct location for the hole.

If you tap with a cordless drill be sure to use plenty of cutting oil. If you don't use oil the tap will break often.

Jim

[SteveHGraham]

I got one of those doodads Sears sells.

Wait, I found it. It's a drill guide.

http://www.sears.com/shc/s/p_10153_1260 ... rill+guide

Works fine.

When I first read this thread's title, I thought "hand drill" meant one of those things you turn by hand. I think only Popeye can make those go through metal.

[spro]

Actually a small egg-beater type drill could and did drill through steel a lot. If you only have a few bits and one tool you get really good at sharpness, pressure and lube. When you get to the breast drill where you can really lay into it and it's 2-speed that would be better. There were all kinds of attachments for them. Ramp type semi impact and the chain drill attachment. Pretty cool. It just tightened up the pressure like a drill press.

[Russ Hanscom]

I'm with Spro - but not going to dig it out and use it unless it is essential to restoring electric power. Two speeds and a ratchet - a hot tool for the time

For those who have never seen the setup.........

[jpfalt]

My method has been to center punch and then predrill with a small diameter drill, say 3/32 or 1/8. Then follow with the full size drill.

Most of the cutting force in drilling is to push the thickness of the drill point through the material being drilled. The small drill goes through relatively quickly and the large drill will nearly feed itself through.

[spro]

There are "drill bushings" which aren't really bushings but guides. They are hard stuff with two dia o s. they come in all i s dia. generally they would go into a fixture outside the work and act as a guide so the drill bit won't bend. They have a setscrew so can act as a guide or strengthen the bit where it may try to bend. nobody does that but it's possible.
If the spacing of the holes is a consistant measure then a flat bar of metal with the excact finish hole(or two) plus the pilot hole dia can be placed on the workpiece. Each gets guided by the one that is right by a shaft or screw of that dia locating it by reference to the other.

[CB&Q]

.... If you don't use oil the tap will break often.
Jim

Errrr, excuse me..... my taps only break once.

But my taps often break.

I say a nit-picker like me ought to be shot, no?

CB&Q

[Russ Hanscom]

Well, technically, you are correct.

[davec43]

maybe Jim sharpens his