which center bits to buy

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workinforwood

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I need to buy some center drills, but there are so many options that I can't figure out which ones to get. I see ones that drill and countersink both one sided and two sided. I see ones that do not countersink, just like a regular drill bit but very short of course. And I see ones that almost look like a super short drill bit but have a hole that goes all the way through it<hole through cutter, not all the way up through the shank>. And then..what type of metal is going to hold up the best for drilling metals?
 
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Daniel

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Best price I know of is the little machine shop, you can buy them individual there also. I use just the plain reaming double ended style. they are not real big on durability. not sure about what type is best but these do work fine for metal, that is until the tip breaks off, then spin it around and break the other end.

The taper it cuts helps center the twist bit when you switch to it. the little hole it cuts before it cuts the taper is to hit and hold the center of the material you are drilling.

As a plus the taper fits a 60 degree live center as well.
 

me2cyclops

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buford GA
"As a plus the taper fits a 60 degree live center as well."

this is what the are designed for , spotting drills are for starting holes
but in wood and plastic center drills work just fine.

BTW how are you breaking them I have used several cheap ones for many years . I run out of room to resharpen but have never broken one, sounds like your tailstock is off or your drill chuck isn't holding straight.
 

skiprat

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I normally use the double ended HSS bits. Like in the pic. I have never had a problem with them breaking and use them a lot on stainless steel.
I used to buy them in sets of various sizes ( mainly cos they came in a box )
But I found that I needed one size much more often than others and now get them individually. The ones in the pic are tungsten carbide but the HSS ones look the same
 

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Daniel

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I break them one because I am using the smallest ones and trying to drill to fast or let them get dull. I have not broken the larger ones. The turn it around and break the other end was meant to be funny.

"As a plus the taper fits a 60 degree live center as well."

this is what the are designed for , spotting drills are for starting holes
but in wood and plastic center drills work just fine.

BTW how are you breaking them I have used several cheap ones for many years . I run out of room to resharpen but have never broken one, sounds like your tailstock is off or your drill chuck isn't holding straight.
 
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