I know what it is, but I dont know exactly what it is...

[cuemaker]

When I purchased an old SB lathe, I got the original owners tool box. There were over 75 taps (a good portion new and unused) and about 50 drill bits. Out of the drill bits, a serious majority of them are sizable but with a taper.

I dont know much about tapers, but after Googling part numbers, tapers and measuring, I still dont know.

Picture is an example of a new Cleveland Twist drill bit, made in the US. 9/16. The calipers show the length of the taper, and 1st picture is the width at the top of the flat part.

What taper is it?

[sch]

Looks like MT2 taper to me, after eyeballing a few of my taper drills.

[cuemaker]

Ohhh gosh, I hope not (because I will look stupid).... but really hope so...

I thought I tried to put it in my tailstock and it was to small.

What is the flat spot for?

EDIT>>>>>>> It is swallowed up by my tailstock which is a mt2

[gwilson]

Looks like a #1 to me. That is only a 9/16" drill.

[J Tiers]

Looks like a #1 to me. That is only a 9/16" drill.

Measurements are about a MT1 indeed.

length is different due no doubt to a somewhat longer overall length..... my MT1 are about 2.14 to the same point on the tang, but it is common to have extra length when the drill or arbor diameter is larger than the MT at fat end.

0.451 is about right for "about there" on an MT1.

[cuemaker]

I measured and measured.. but didnt fit into the MT 1 based on what I read for "max" this and that.. so I thought maybe something exotic... But my call a friend option says MT 1, so thats what I will be going with..

Next question.. is the flat spot for a set screw?

[EddyCurr]

I dont know much about tapers

It is swallowed up by my tailstock which is a mt2

Looks like a #1 to me.

You may or may not be aware that 'Steel Drill Sleeves' to adapt
a 1MT shank to a 2MT bore are readily available and inexpensive.

An off-shore brand at Travers is less than $10, a Collis is less than $30.
The MSC & Enco sites are offline at the moment, but their prices are likely
similar.

.

[toolmaker76]

I have not seen that flat spot on drills before, but I have noticed my Sheldon lathe with MT2 taper does not have anything inside to keep the drill from spinning. I have thought about putting a setscrew on the tailstock to keep larger drills from spinning.

It hasn't been much of a problem to date, but I have some work coming where I am going to need to uses some larger drills. I am wondering if that is some sort of provision for the same thing.

On most machinery I have used to date, there are flats in the tailstock that grip the flats on the tang, preventing the drill from spinning.

[EddyCurr]

Nor have I, but I don't get out much.

In any event, isn't the flat spot far enough up the shank to be at or beyond
the end of a tailstock or a sleeve when the drill is seated? If this is the case,
perhaps it is intended to assist with removal.

.

[Jaakko Fagerlund]

If your Morse taper drill bit rotates in a Morse taper, then there is something wrong with the taper in either the holder or the drill bit.

[Forrest Addy]

Might be a #5 B&S. I dont know about that funny flat. It's ramped against the taper. Maybe for a set screw to hold the drill in the socket?

Is the taper about 1/2 per ft and the taper lenght 2 1/8" there abouts. It wasn't unusual on B&S tapers to extend the big end if needed to legthen the tool.

Has to be an oddball but recent. Look at the poly packaging tube. No bar code so it can't be TOO recent.

We used to have some old close quarters tooling that shaks like Jabobs tapers but has an integral flat. WW II era. Very handy. I used some of it for out of the way, tucked in behind drilling on a missle mount back when I was skinny and flexible.

[rohart]

If you're still in doubt about which taper it is, you need to measure the angle accurately.

Taper tables should specify the angle of each taper, but if you only have the e 'taper per length' specs, then you have to convert this to the angle.

You measure the angle best by mounting the drill in the lathe, centre to centre, and using a DTI mounted at centre height in the tool post.

Manufactured tools can vary in length, but the angle has to be correct for the taper.

I agree that the flat could be for either a drive pin or a removal cam.

As for the flat on the end, called a tang, the discussion about whether it is meant to help drive the tool or not will go on forever, but it does look like a Morse taper tang to me.

[jugs]

When I purchased an old SB lathe, I got the original owners tool box. There were over 75 taps (a good portion new and unused) and about 50 drill bits. Out of the drill bits, a serious majority of them are sizable but with a taper.

I dont know much about tapers, but after Googling part numbers, tapers and measuring, I still dont know.

Picture is an example of a new Cleveland Twist drill bit, made in the US. 9/16. The calipers show the length of the taper, and 1st picture is the width at the top of the flat part.

What taper is it?

I'm not getting a picture

[boslab]

there was some 'anti spin' mt drill sleeves about, they had a grub screw to stop the spin, this might be one of these, i only saw an example of one in a metalwork class.
just an idea
mark

[cuemaker]

Jugs,

The pictures are massive (I like really big pictures), but here i a link to my photo bucket so you can see them..

http://i201.photobucket.com/albums/aa129/xringx/DSCF0094.jpg

http://i201.photobucket.com/albums/aa129/xringx/DSCF0095.jpg