Julie, research Drill Doctor. Essential for smaller drills imho. Hand sharpening tricky for small dia. Drills.
Btw, I operated screw machines & 5 spindle Davenports . Both these machines taught me lots about twist drills. Google screw machines.
is it just me, or have burs and twist drills gotten 3x more expensive?!?
i am a hoarder, so i dont buy them often…i am now seeing prices of like $24, where they used to be $9…
this is what i am looking for…i thought i found them…but when i click in to a size option, the drill doesn’t look like main pic, with shorter twist area…
I had a really good experience finding 1/4" and 3/8" square W1 tool steel from McMaster - Carr recently. The shipping was quick and very reasonable. I am putting together another shopping list right now…Rob
i did just order a few sizes of the carbide pave drills from Rio (mentioned above) …then, a friend mentioned that carbide is very brittle…she broke hers right away😳…
they were a bit pricey! i wil need to be careful!
any advise on the proper use of carbide drills would be greatly appreciated!
Carbide drills are entirely unnecessary for precious metals. High Speed Steel drills are preferable. They are less brittle and while they will dull, eventually, learning to sharpen small drill bits is easy. One reason is that the difference in hardness between steel and gold/silver/copper is so great that the angles you sharpen to are very forgiving. The bits will still cut even if you are not at the perfect angle for the particular metal.
hi Elliott,
ok, great to know! I wanted to try the shorter drill and the pave dtills had the appearance i was looking for…but! i am gonna try the micro drills you suggested too, much better price!
…i could try one size carbide pave drill, and possibly return the other sizes carbide pave drills…
i also saw these interesting combo pave drill/burs…saw a video about them…looked interesting…i am such a sucker for new tool videos!
Sooo…HSS short split shank drill bits are what I’ve been looking for all these yrs.
Odd how not one of my instructors ever told me about these distinctions in the simple drill bit!
Now, about ordering these…None at Rio…M-C with all the detailed charts is confusing…
I work in silver/copper/bronze, and use drills frequently. The skipping is my #1 fear - I’ve ruined many pieces due to that ;even with a “pilot mark” , and I had never heard of a split shank until today!
Also - a question: what are “twist drills” specifically for? I’ve used drills that are given to me that I now know are called “twist drills” but they broke so easily…
hi Lori,
re the M-C website and that link to micro drill page…
at top of left side nav bar, you can click on “mm” or “inches”… might help to shop!
i am used to mm…i use mostly .5mm to 1.0mm
what sizes do you mostly use?
.5mm sooo delicate!
i have a hand spiral twist drill that i use with .5mm drills to drill/ start the seat for them first, on the punch/ scribe mark…works pretty good…i have not yet been able to master going in fast!
“Twist drill” refers to the type of drill bit.
The most common type of drill bit these days is the twist drill. They are designed for drilling holes in metal. They are called twist drills because of the spiral flutes that run up the shank, which clear the chips from the hole as it is being bored. This was a big deal invention. Before them drill bits for metal were D-bits and spade bits. These have solid shanks and so must be withdrawn from the hole frequently to clear chips.
For drilling holes in wood the old type of bit is what is called a spoon bit. The modern types are augurs, spur bits, and most recently Forstner bits.
Clickspring, an Aussie machinist channel, has an excellent video on making a traditional pump drill with handmade spade bits. It is part of his series on reconstructing the Antikythera Mechanism. Very interesting, as is his entire channel.