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Triangle Drill Bit Shank

dav1965dav1965 Member Posts: 26,540 ✭✭✭
edited January 2017 in General Discussion
Triangle shank

The triangle shank is similar to a hex shank in that it is angled, but it only has three angles to the hex's six. It features many of the same strengths as the hex, including high torque capabilities and good centering. However, it cannot attach to quite as many different drill chucks as the hex.

I got a set today at the pawn shop. They are all very old and looks like it is just for drilling wood because of the centering tips and the flutes on the bit.

What were they made to go in?

They are in great shape and i would hate to cut the end off to make them work in a regular drill.

I would rather buy the right tool and save these like they are. I am thinking it could even be hand operated.

Any ideas?

Comments

  • Mr. PerfectMr. Perfect Member, Moderator Posts: 66,438 ******
    edited November -1
    I've never had any problem using them in a regular drill.
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    And fiery auto crashes
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  • AlpineAlpine Member Posts: 15,092 ✭✭✭✭
    edited November -1
    Three sides on the shank of the drill bit is to give the drill chuck (which has three jaws to clamp onto the drill bit) a better grip on the drill.

    When you insert the drill bit into the chuck make sure the flats and the jaws line up and the drill will not slip.
    ?The problem with socialism is that you eventually run out of other people's money.?
    Margaret Thatcher

    "There are three kinds of lies: lies, damned lies and statistics."
    Mark Twain
  • AzAfshinAzAfshin Member Posts: 2,985 ✭✭
    edited November -1
    You can't fit those into collets or collet style holders, but drills should be fine.
  • cbxjeffcbxjeff Member Posts: 17,626 ✭✭✭✭
    edited November -1
    If your bit shanks have 3 flat sides that are not also tapered, you are good to go. Most chucks have 3 jaws. Now if your bits have tapered shanks at the chuck end they were made for what we old guys remember as a brace and bit tool.
    It's too late for me, save yourself.
  • dav1965dav1965 Member Posts: 26,540 ✭✭✭
    edited November -1
    All the bits are triangle at the top and drop off to a point n the end.

    I could probably use them in a drill like they are but if there is a special tool to use them i would love to have that tool.
  • dav1965dav1965 Member Posts: 26,540 ✭✭✭
    edited November -1
    I found it it is called a shank drill bit.
  • LesWVaLesWVa Member Posts: 10,490 ✭✭
    edited November -1
    Had a bunch of three sided shank drill bits in a machine shop. They were used in a three jaw chuck on a lathe for drilling stock.
  • AlpineAlpine Member Posts: 15,092 ✭✭✭✭
    edited November -1
    quote:Originally posted by AzAfshin
    You can't fit those into collets or collet style holders, but drills should be fine.



    Actually they work fine in a collet. The grip surface on a collet is much greater than any drill chuck (which is only holding on the three jaws).

    Just try to use a Geometric Die head on a 3 jaw held piece and see how it slips vs. a collet held piece.
    ?The problem with socialism is that you eventually run out of other people's money.?
    Margaret Thatcher

    "There are three kinds of lies: lies, damned lies and statistics."
    Mark Twain
  • OakieOakie Member Posts: 40,558 ✭✭✭✭
    edited November -1
    I but these a lot at auctions. I cut the ends off and just use them that way.
  • AzAfshinAzAfshin Member Posts: 2,985 ✭✭
    edited November -1
    quote:Originally posted by Alpine
    quote:Originally posted by AzAfshin
    You can't fit those into collets or collet style holders, but drills should be fine.



    Actually they work fine in a collet. The grip surface on a collet is much greater than any drill chuck (which is only holding on the three jaws).

    Just try to use a Geometric Die head on a 3 jaw held piece and see how it slips vs. a collet held piece.





    Isn't the inside of collets round with a morse taper (usually)? That would only grip the shank on the three points of the triangle, and then only at the very end of the shank due to the taper. I suppose if you had a specialty three sided collet that wasn't rounded and tapered, that would work. But honestly I've never see one of those.
  • AlpineAlpine Member Posts: 15,092 ✭✭✭✭
    edited November -1
    quote:Originally posted by AzAfshin
    quote:Originally posted by Alpine
    quote:Originally posted by AzAfshin
    You can't fit those into collets or collet style holders, but drills should be fine.



    Actually they work fine in a collet. The grip surface on a collet is much greater than any drill chuck (which is only holding on the three jaws).


    Just try to use a Geometric Die head on a 3 jaw held piece and see how it slips vs. a collet held piece.





    Isn't the inside of collets round with a morse taper (usually)? That would only grip the shank on the three points of the triangle, and then only at the very end of the shank due to the taper. I suppose if you had a specialty three sided collet that wasn't rounded and tapered, that would work. But honestly I've never see one of those.



    No. Collets have straight inside walls. Morse taper is fixed and Morse Taper sizes start with 1 and it is about 3/8" diameter. R8 collets (for bridgeport type mills, 5C for lathes and fixtures (indexers and rotory tables), 2J for lathes (comes in bigger sizes than 5C). ER series is for tool holding in milling machines and used in some lathes.

    There are specialty tooling for specific machines, coolant thru drills and lots of other stuff.
    ?The problem with socialism is that you eventually run out of other people's money.?
    Margaret Thatcher

    "There are three kinds of lies: lies, damned lies and statistics."
    Mark Twain
  • JimmyJackJimmyJack Member Posts: 5,509 ✭✭✭✭
    edited November -1
    I prefer them over a round shank, no slippage. Would be a shame to cut off the end.
  • woodshed87woodshed87 Member Posts: 23,478 ✭✭✭
    edited November -1
    quote:Originally posted by JimmyJack
    I prefer them over a round shank, no slippage. Would be a shame to cut off the end.

    YEP[^]
  • TRAP55TRAP55 Member Posts: 8,292 ✭✭✭
    edited November -1
    Brace and bit?

    antique-brace-bit-08339.jpg
  • AlpineAlpine Member Posts: 15,092 ✭✭✭✭
    edited November -1
    quote:Originally posted by TRAP55
    Brace and bit?

    antique-brace-bit-08339.jpg



    I have my Dad's old carpenter tools. The brace and bit along with some blade bits for the brace made it the the "power tool" for hanging doors in the day. Jack and block planes and super sharp chisels fill out the tool box.

    If I remember correctly those self feeding drill bits had a 4 sided tapered shank. The jaws of the brace had 2 jaws that tightened on the tapered shank.
    ?The problem with socialism is that you eventually run out of other people's money.?
    Margaret Thatcher

    "There are three kinds of lies: lies, damned lies and statistics."
    Mark Twain
  • cbxjeffcbxjeff Member Posts: 17,626 ✭✭✭✭
    edited November -1
    Exactly what I was trying to explain earlier, Alpine. I didn't have the pic like you did though. If you use those in a check or collet you will end up with what approaches a 3 point contact surface. Don't try.
    It's too late for me, save yourself.
  • AlpineAlpine Member Posts: 15,092 ✭✭✭✭
    edited November -1
    quote:Originally posted by cbxjeff
    Exactly what I was trying to explain earlier, Alpine. I didn't have the pic like you did though. If you use those in a check or collet you will end up with what approaches a 3 point contact surface. Don't try.


    A tapered 4 point shank self feed drill is very, very different from a straight shank drill with three flats ground on it. Night and day difference.

    Apples and Oranges.
    ?The problem with socialism is that you eventually run out of other people's money.?
    Margaret Thatcher

    "There are three kinds of lies: lies, damned lies and statistics."
    Mark Twain
  • grdad45grdad45 Member Posts: 5,380 ✭✭✭✭
    edited November -1
    quote:Originally posted by TRAP55
    Brace and bit?

    antique-brace-bit-08339.jpg

    You have the answer!!! I used them years ago when roughing in house wiring. Labor intensive to say the least.
  • montanajoemontanajoe Forums Admins, Member, Moderator Posts: 60,191 ******
    edited November -1
    quote:Originally posted by Alpine
    Three sides on the shank of the drill bit is to give the drill chuck (which has three jaws to clamp onto the drill bit) a better grip on the drill.

    When you insert the drill bit into the chuck make sure the flats and the jaws line up and the drill will not slip.




    Yes,,+1
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