Are you sure that’s technically a drill bit and not some sort of machine tool or die for a c&c machine. Most of the associated videos that pop up after that one finished seem to deal with that sort of thing. More complex things for machining metal, not really something I could toss in a hand drill and use at home.
Sounds about right to me. And if I’m remembering correctly the bit is the drill terminology only otherwise applies to antique type hand drills where the bit was the tool (and thus the drill) and whatever handle was affixed was incidental or applied later. Like I’ve often seen the old hand cranked style handle/holder referred to as a brace and the bits they would use referred to as a drill regardless of what it was mounted to.
I believe that video is of a wobble broach in a vertical end mill, and not a drill at all. Big $$$$$!
You can use an old-fashioned square mortise bit to drill square holes, though.
There’s also a tool called a “chain mortiser” that’s used to cut large square mortises for sill tenons in timber framing. It’s not a drill, though, it’s much more like a chainsaw, and also not cheap.
@hotel, @Ryuthrowsstuff: I suspect the word “bit” is etymologically derived from “bite”. In the same way that the “bitter end” of a rope is the part that will bite you. I have used eggbeater drills (technically called “hand drills”) and I’ve played with an old chest drill, and I have a very nice brace that my grandfather left me. All three of those use drill bits (although they aren’t interchangeable). Old augers from the 1700s have a handle and a bit; usually the handle is permanently affixed.
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So, spade or forstner for trepanation?
You can send it to me, I’ll take a pic and upload it.
Oh, and yeah, return it to you of course!
I do a lot of steel, and higher speeds with carbide bits, and adequate lubrication is essential for any significantly hard materials. For softer steels, you can actually get away quite nicely with slow speeds and oil lube with a HSS or Cobalt bit for most smaller holes.
Really a terrific post and conversation!!
This may be old-hat for most people on here, but to add on to @kmoser’s comment about how to reduce damage when drilling:
For laminated plywood, plexglass, or coated MDF - use some painter’s tape on the reverse side of the punch, and definitely start small working up in bit size. That’ll protect the finish. You can start by drilling a pilot hole to place the tape. That way you won’t be marking up needlessly.
Also, I have the joy of living in a condo with plaster walls. For people who haven’t dealt with plaster: unlike wallboard, plaster will crack and rip on the face if you don’t treat it with care. Drill a pilot hole first, then step up slowly, and the older the plaster, the more careful you should be.
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For me one of those old hand drills (and I have still got one) used to be called a ‘bit and brace’. I don’t know if I had an old school carp. shop in the UK but that’s what it was called. The brace typically had a two-sided bit with a square notch in it: it could take square and round drills. The bits were typically square at one end, and flat-ended with a small centering screw.
I lay my angle-grinder on its back and sharpen the bit pointing down. Getting the pitch and angle right takes a bit of practice. Only used for wood and steel bits. Masonry bits i just chuck when they’re done. Although the blue-striped Bosch masonry bits are the best you can get, they stay sharp forever.
You can use the painter’s tape when drilling into glazed tiles also, to stop the bit sliding around.
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Great post! I love it when an esoteric topic I know something about appears on BoingBoing.
I specialize in cutting metals and there were just a few points that I wanted to add.
- Drilling Speeds:
Just to make the article a little clearer, drilling speeds depend on three things: the hardness of the material you are drilling, the size of the drill, and what the drill is made of. In general:
- the harder the material, the slower you want the drill to spin.
- the larger the drill, the slower you want the drill to spin.
- the harder the drill, the faster you want the drill to spin
- How much pressure to apply to the drill OR How fast should you try to push the drill through the material?
The article says:
“Let the tool do most of the work, applying steady pressure directly parallel (presumably perpendicular) to the bit. If you’re leaning into it and nothing happens either the bit is dull or you’re using the wrong kind for your material.”
This is definitely correct, but just to elaborate a bit, there is a very tight connection between how fast your drill is spinning and how fast you can open the hole. A drill that is spinning quickly is able to open a hole much faster than a drill that is spinning slowly. Also, at least with metal, as @hotel suggested, pushing too slowly can cause excess heat build up and lead to things like premature dulling of the blade.
- Drill Composition or What the Drill is Made Of
I think the article got it slightly wrong on this count, or uses a terminology that I have not heard of. It says:
“From softest to hardest are Steel, High Speed Steel, Carbite Tipped, and Cobalt steel.”
The softest drills are indeed regular steel. I would imagine that a steel drill would work for most applications other than metal.
The second softest is High Speed Steel, although within the category of high speed steel you will have various compositions that allow for various capabilities. Many high speed steel drills contain a significant percentage of cobalt which makes it more heat resistant.
The hardest material is Carbide. Carbide is very expensive and so you might use a carbide tipped drill instead to save money. Also Carbide is very hard but also very brittle meaning that it is prone to breaking. I would imagine that there are very few circumstances where you would need a carbide drill if you are not a professional machinist.
- And finally sharpening drills
If you have a grinding wheel, you can try sharpening a drill, but it’s surprisingly difficult. From my experience, it takes several years of practice to get good at it. I’ve only been doing it for a couple of years but I only get it right once every few times. If you are going to do a significant amount of drilling, you might want to invest in a specialized piece of equipment like a Drill Doctor like @Groundman
Well that’s about it for me. Let me know if you want to talk more about tools!
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i’m going to give this one more try. how to i post a photo (of my 24k gold) drill bit on this busines here? i’ve been trying for years to participate in any number of these conversations. never once successfully.
I think that the BBS restricts images on new accounts as anti-spam measures and the like. Best way of posting an image would be to up it to an image-sharing site like Imgur and put an indirect link (i.e. not one ending in *.jpg ) to it here. Not ideal, but we’ll able to see it then.
Edit: The Discourse BBS system usually assigns user trust levels by activity. To go from “new user” which has very restricted options to “basic” when you can post images, have a browse around the forums for a bit. After a certain amount of activity (not exactly sure how much, sorry. ) , it should trigger.
Or spoon?
Spoooooooon!
The bit is called the “tool,” at least in the (western U.S.) machine shops I’ve worked in. This was in CNC mills and lathes, we didn’t screw around with hand drills. It may vary by region or industry though. And swarf was called “chips,” even if it was more like ribbons.
I find inch sized bits surprisingly hard to get in my neck of the woods.
/duck
Which one is best for getting the brains out? Forstner?
There’s some urgency here.
You left out my favourite and cleanest cutting bit for wood, the Brad Point (sometimes called a Dowel Bit).
The Brad Point is the combination of the best cutting aspects of a Spade Bit, Forstner Bit and a Twist Bit, however at first inspection looks just like a pointier Twist Bit. Brad Points make exceptionally clean holes, and with their centre point are good for precise work.
Oh my, that’s a thing of beauty!
It might be used by a CNC, but on a drill press with adequate stabilisation I assume it would work as well
