hole saws vs. Milwaukee contractor’s bit
alecs
| Posted in Tools for Home Building on
I wanted to get a hole saw kit, you know, for drilling holes. Then I saw Milwaukee’s self-feed contractor’s bit kit on Amazon/tool crib, it’s called the 49-22-0130.
I’m not familiar with this self-feed type of drill. Anyone care to share their experience with these, vs. traditional hole saws? Pros and cons?
They would be used for cutting mostly wood and plastics. I don’t like the rough holes and shallow depth limits on hole saws, and then getting the slug out of the saw is a pain too. Can you cut metal with the self-feed bits?
Thanks
Alec
Replies
Those self feed bits do not work well going through OSB. Pieces flake off and cover the cutting edge. Sometimes plywood does the same thing.
In regular wood, they do cut faster than a hole saw- until you hit a nail.
They probably won't work in plastic, definitely not in metal.
Carbide tipped hole saws- while expensive- do cut much faster than the bi-metal variety. The cut is better, too.
A big hole saw takes a big drill.
I find thin metal cutting to go better when the hole saw is run in reverse. Try a cut in aluminum siding and you will understand.
An annular cutter does a better job making holes in reasonably thick metal.
You summed the situation up pretty well IMHO.I will add that there are deeper hole saws available. Up to 2-1/2" as I understand it. Standard ones are 1-1/2" so often even going through a 2by takes a shake or backing out, prying the center plug out and a bit more work with the holesaw. Especially true on old work where the 2bys are closer to a full 2".There are a few hole saw arbors that have a large thread ram that will press the plug out of hole saw. Some work. Other less so. IMO it is often as easy to remove the saw body and once off the arbor a piece of dowel, punch or large screwdriver will back the plug out quickly.Those contractors bits, saw edge self-feed bits, don't handle nails or concrete well. In larger sizes it is easy to bung up a $50 bit in seconds. Of course if your careful usually this can be avoided. Sometimes not.Self-feed bits are the Cadillac of wood bits. Similarly there are 'hole cutter' or the more specialized 'annular cutter' bits for metals and some tough materials. They are like hole saws with heavy bodies and a few large carbide teeth. A 7/8" bit might have two or three teeth and go for $30. They are great for sheet metal and metal plating but like the self-feed model intended for wood they are not cheap. They cut well, don't chatter or bind often and leave a nice round hole with little or no burr. They really speed cutting holes for conduits in boxes. One of the few effective cutters for stainless enclosures. Use cutting fluid and very firm pressure to keep them cutting and sharp longer. Failing to do this in stainless can quickly dull them but the good news is these units can be resharpened a few times professionally.The standard saw-edged hole saws are a compromise. Less efficient but quite adaptable in that they will eventually cut a decent hole in many common materials and, if you run into a hardened nail, concrete or just get old and dull they are relatively cheap to replace. In a pinch a dull unit can be roughly sharpened with a three-square file to get a hole or two out of them without having to 'burn the holes' through. For a bit more money there are hole saws that have titanium nitride coated teeth, tiny carbide inserts on the teeth that wear more slowly. Or carbide grit teeth that will slowly cut concrete or stone but all these get to be progressively more expensive and start to approach the cost of the high end units without gaining much in speed.
> I find thin metal cutting to go better when the hole saw is run in reverse.
What I have for thin metal is a set of chassis punches. You just drill a 3/8" hole for the center, put the bolt of the punch thru it, screw on the die, and turn until it pops thru. They make very clean holes.
-- J.S.
I have a Roper Whitney #5 JR hand punch- great for holes 1/4 inch and smaller about 1.5 inches or less from the edge.
I thought about something like Greenlee knockout punches, but I don't need something like that often enough. The Greenlees don't punch nicely in thin gauge stock- at least that is my experience.
Mine seem to do fine in thin stuff. Got them real cheap at an auction a long time ago. They're not something I'd be able to justify buying retail.
-- J.S.
I use my Whitney punch everyday. A few years ago I asked my youngest daughter what she wanted for Christmas. Her reply, "A Whitney punch, just like yours!" My father was a tinner and he used his everyday too. Best darn thing for holes in sheet metal and even leather.
I saw a Chinese knock-off of one. It had the same minor casting flaw as mine.
Real wood & thick plywood I use the self feed bits & being a plumber I use the big ones 4&5/8" ones.
OSB & plastic those single tooth carbide ones are great.
Metal studs I use a plasma cutter
Self feed bits you can sharpen or have them sharpened I have never heard of anyone sending out a hole saw to be sharpened.
Electritian heard that I owned a 6" hole saw and asked to borrow it. Not thinking I pealed the plastic from the virgin teeth and handed it over. At the end of the day it wouldn't cut butter. He was running wires through an existing wall and would cut the sheetrock at each stud with the 6" hole saw to drill and fish the romex along. Great for him.
Anyway, 10 minutes with a diamond file and the teeth were almost sharp as new.
I keep a small (6") mill file with me to sharpen the self feed bits after the nail encounter. Directions come with the bits. Yes it takes some time, but so does taking the plugs out of hole saws. For big self feed bits (3"+) you need a drill with power, like the Milwaukee Hole Hawg. Again, if ones just needs a few holes, the expense of self feed bits may not be warranted.You can never make something foolproof because fools are so ingenious.
We cut through copper and soffit wood witha 4" holesaw and a 12" pilot bit...often hit nails in old soffit corners. With a cordless angle grinder and a cut off wheel, I can re sharpen a hole saw in about a minute.
Gotta admit tho', I love them big selffeeds in solid wood, just to see the potato chips they make ..
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