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Metalworking (rec.crafts.metalworking) Discuss various aspects of working with metal, such as machining, welding, metal joining, screwing, casting, hardening/tempering, blacksmithing/forging, spinning and hammer work, sheet metal work. |
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#1
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Drill bit question
SteveB wrote: I bought a bunch of drill bits at yard sales recently. Some only have flutes about a third of the way up the shaft, then clear shaft. They're as long as normal bits, so they haven't been resharpened until becoming that short. Can someone explain these to me? Steve They could be spotting drills or just a special ordered drill. Spotting drills are used to locate or spot a drilled hole. They are made with short flutes so they will be still and not wander when they first touch the metal. John |
#2
Posted to rec.crafts.metalworking
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Drill bit question
I bought a bunch of drill bits at yard sales recently. Some only have
flutes about a third of the way up the shaft, then clear shaft. They're as long as normal bits, so they haven't been resharpened until becoming that short. Can someone explain these to me? Steve |
#3
Posted to rec.crafts.metalworking
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Drill bit question
john wrote:
SteveB wrote: I bought a bunch of drill bits at yard sales recently. Some only have flutes about a third of the way up the shaft, then clear shaft. They're as long as normal bits, so they haven't been resharpened until becoming that short. Can someone explain these to me? Steve They could be spotting drills or just a special ordered drill. Spotting drills are used to locate or spot a drilled hole. They are made with short flutes so they will be still and not wander when they first touch the metal. John I have seen something similar used in places that work primarily with thin material and sheetmetal type stuff. The work piece is never very thick so you don't need full length flutes, but still have enough length on the bit to reach places that a stubby bit would not. I suppose it makes them more rigid and perhaps less expensive. There is a generic name for them that is escaping me right now. |
#4
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Drill bit question
On Fri, 24 Aug 2007 16:11:22 -0700, "SteveB"
wrote: I bought a bunch of drill bits at yard sales recently. Some only have flutes about a third of the way up the shaft, then clear shaft. They're as long as normal bits, so they haven't been resharpened until becoming that short. Can someone explain these to me? Sounds like what I know as aircraft drills. Though I've never poked holes in airplanes, I assume they're intended for drilling thin materials in awkward spots where the extra stiffness of the unfluted shank is desirable. -- Ned Simmons |
#5
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Drill bit question
"Al A." wrote:
john wrote: SteveB wrote: I bought a bunch of drill bits at yard sales recently. Some only have flutes about a third of the way up the shaft, then clear shaft. They're as long as normal bits, so they haven't been resharpened until becoming that short. Can someone explain these to me? Steve They could be spotting drills or just a special ordered drill. Spotting drills are used to locate or spot a drilled hole. They are made with short flutes so they will be still and not wander when they first touch the metal. John I have seen something similar used in places that work primarily with thin material and sheetmetal type stuff. The work piece is never very thick so you don't need full length flutes, but still have enough length on the bit to reach places that a stubby bit would not. I suppose it makes them more rigid and perhaps less expensive. There is a generic name for them that is escaping me right now. Yup. Some of the short flute drills are used with sheetmetal work. I used them for many years. The short flute on them was nice because when you came to the end of the flute you kept going to clean the little bit of metal left in an otherwise round hole. For riveting this was essential to get the rivet to go into the hole. I used to buy them from a guy that had a boothe in the Ft. lauderdale Thunderbird flea market who sold tooling, drills and a bunch of other related stuff. The spotting drills have a different angle than the other drills. the spotting drills are usually 90 degrees. John |
#6
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Drill bit question
On Fri, 24 Aug 2007 16:11:22 -0700, "SteveB"
wrote: I bought a bunch of drill bits at yard sales recently. Some only have flutes about a third of the way up the shaft, then clear shaft. They're as long as normal bits, so they haven't been resharpened until becoming that short. Can someone explain these to me? Steve click on http://www.wttool.com/product-exec/p...nd_Body_Drills http://www.wttool.com/category-exec/category_id/14485 Unka' George [George McDuffee] ============ Merchants have no country. The mere spot they stand on does not constitute so strong an attachment as that from which they draw their gains. Thomas Jefferson (1743-1826), U.S. president. Letter, 17 March 1814. |
#7
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Drill bit question
I have some medical drills that are like this; long shaft and short
flute length. -- Jedd Haas - Artist - New Orleans, LA http://www.gallerytungsten.com http://www.epsno.com |
#8
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Drill bit question
"SteveB" wrote in message ... I bought a bunch of drill bits at yard sales recently. Some only have flutes about a third of the way up the shaft, then clear shaft. They're as long as normal bits, so they haven't been resharpened until becoming that short. Can someone explain these to me? Steve They're called "Kaufmann" drills. I don't know how I know that. |
#9
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Drill bit question
SteveB wrote:
Some only have flutes about a third of the way up the shaft, then clear shaft. They are for sheet metal work. Nick -- The lowcost-DRO: http://www.yadro.de |
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