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Starting holes with a rotary tool?

First. Sorry, but what is it called, that hard steel pencil-like thing used for starting to drill a hole? You hammer on it to make a small dent in the metal before drilling.

Anyway, when hammering on the project is not practical, I'd like to use a rotary tool bit to start the hole. Planning to try the V-shaped high- speed steel bit (125) later today. It's for aluminum and I guess that bit would not be appropriate for steel. I'm wondering if some other rotary tool bit might work for both. I've tried carving/engraving and another high-speed cutter (100) which chattered too much in the aluminum even at high speed. Maybe one of the tungsten carbide cutters bits?

Reply to
John Doe
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Center punch?

There also exist automatic center punches you don't have to hammer on. Never used them.

Nick

Reply to
Nick Müller

center punch

never heard of using rotary tools for that...

i
Reply to
Ignoramus32681

A Prick Punch has a slender point that you can align with scribe marks, then tap lightly to make a small dimple which you enlarge with a blunter Center Punch to guide the drill bit's point.

A Center Drill is a rotary tool that will start a hole without wandering.

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Jim Wilkins

Reply to
jim.wilkins

You could also try a spring-actuated center punch, which is not hit with a hammer. You push it with your hand and the spring inside fires the punch part into the metal with more force than your hand. No hammering required. Then center-drill (short, stubby starting tool that doesn't wander. Then use short, regular drill bit. BTW, Most high-speed steel cutters are appropriate for steel, they just aren't that effective. Chatter is a fact of life with these cutters because they do have teeth. The structured tooth carbide cutters are a slight possiblility, but I don't think that they come in a cutter with any kind of point because it would be too brittle and would break off.

Reply to
woodworker88

I think you would be very satisfied with a center drill. Check Enco or MSC. They come in various sizes and they're very inexpensive. They work well both on aluminum and on steel, can be used in a lathe, drillpress, mill or hand drill.

Reply to
Don Foreman

The replies look like the concise guide to starting a hole, thanks.

Maybe lack of familiarity causes my inability to distinguish what's going on in this picture (the photography is great).

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Thanks for the alternative suggestions. For the moment, the Dremel 100 bit connected to the flex shaft on low speed seems to do OK in aluminum. The 125 bit didn't work for me at all.

Thank you.

Reply to
John Doe

A center drill drilling a center. :-) OK, the drill on the picture is a "center drill". You could also use a NC-drill (which I prefer on the mill). But both (center drill and NC-drills) are not very good in hand held drills. If the reason why you don't want to use a centerpunch is because you want to drill sheet metal: There are sheet metal drills that don't wander if you start drilling.

Or you explain why to don't want a center punch.

HTH, Nick

Reply to
Nick Müller

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