# MT#2 shell mill holder



## Uncle Buck (Apr 18, 2013)

*MT#2 shell mill holder question*

Here is my question. I want to get some MT#2 shell mill holders for my Atlas MFC horizontal mill. There are two variations sold, the first is a set of 2 holders and is used with a drawbar (I know that one would be well suited for my machine) the second type is a tang type taper and is not tapped for drawbar threads. With that said, the tang set has 3 holders instead of 2 and is a bit cheaper. 

See both sets here http://www.tools4cheap.net/products.php?pg=5 

I am thinking I could just cut off the tangs and drill and tap them for the drawbar and I would be gold. I suppose I might run into some drilling and tapping issues because of the holders being tempered. So what can those smarter than me tell me about this, would you just buy the set of 2 or would you buy the tang set of 3 like I am thinking and remove the tang and drill and tap them yourself? 

Your thoughts on this are welcomed.


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## Terrywerm (Apr 18, 2013)

I've got a hunch that the tang type do not sell very well. Notice the reduced price??  The tang type do have the possibility of coming loose while in use, especially if any side forces are encountered. The drawbar type will stay tight no matter what. 

So, you could save a few bucks and by the tang type, just to have the cutter and arbor pop loose at the most inopportune time. After that happens a couple of times you could then buy the drawbar type, increasing your actual cost due to buying both types just to end up with something reliable. 

My money would be on the drawbar type for a paltry $13 more. Besides, you can only use one at a time, so what would you do with three??


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## Uncle Buck (Apr 18, 2013)

terrywerm said:


> I've got a hunch that the tang type do not sell very well. Notice the reduced price??  The tang type do have the possibility of coming loose while in use, especially if any side forces are encountered. The drawbar type will stay tight no matter what.
> 
> So, you could save a few bucks and by the tang type, just to have the cutter and arbor pop loose at the most inopportune time. After that happens a couple of times you could then buy the drawbar type, increasing your actual cost due to buying both types just to end up with something reliable.
> 
> My money would be on the drawbar type for a paltry $13 more. Besides, you can only use one at a time, so what would you do with three??



The tang type are suited to 3 different sizes of shell mills while the drawbar type misses one of those sizes. Also, I intended to cut the tangs off and drill and tap the tang type effectively converting them into drawbar type holders. I had no intention of actually using the tang type as they are sold but rather converting them. More than anything I was wondering if anyone else thought the plan to convert the tang type holders was a solid plan or not.


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## Terrywerm (Apr 18, 2013)

My apologies, Uncle Buck. I read that in your original post, but for some reason it escaped me. I can see where having the third size might be an advantage at times.

I would think that you might run into some problems with drilling and tapping, as there may well be some heat treatment involved. Cutting the tangs would not be a problem, as they could be cut off using an air powered die grinder with an abrasive cutoff wheel. Drilling could be managed with carbide bits, but that doesn't answer the problem of tapping threads if the metal has been heat treated. I doubt that they are very hard, if they have been hardened at all.

Myself, I would probably purchase the ready made drawbar models instead of taking the time to modify the other ones, but that's just me. My time is worth something, so I would ask myself if getting the third arbor would be worthwhile or not, as the process of cutting, drilling, and tapping would require a time investment at a bare minimum. This plan would be a good one IF you know for sure that the arbors are not hardened.


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## Uncle Buck (Apr 18, 2013)

terrywerm said:


> My apologies, Uncle Buck. I read that in your original post, but for some reason it escaped me. I can see where having the third size might be an advantage at times.
> 
> I would think that you might run into some problems with drilling and tapping, as there may well be some heat treatment involved. Cutting the tangs would not be a problem, as they could be cut off using an air powered die grinder with an abrasive cutoff wheel. Drilling could be managed with carbide bits, but that doesn't answer the problem of tapping threads if the metal has been heat treated. I doubt that they are very hard, if they have been hardened at all.
> 
> Myself, I would probably purchase the ready made drawbar models instead of taking the time to modify the other ones, but that's just me. My time is worth something, so I would ask myself if getting the third arbor would be worthwhile or not, as the process of cutting, drilling, and tapping would require a time investment at a bare minimum. This plan would be a good one IF you know for sure that the arbors are not hardened.



The concerns you voice over the holders being hardened is the same concern I have. That spooks me a little. The thoughts you expressed are exactly my fear in my plan.


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## pineyfolks (Apr 19, 2013)

I came into some #9 B&S tooling with tang arbors a while back, I set them up in the lathe drilled a pilot hole through the center drilled hole in the tang to keep it in line, cut the tang off then drilled to tap size and tap 1/2-13 for my mill. It worked ok for me.


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## Uncle Buck (Apr 19, 2013)

pineyfolks said:


> I came into some #9 B&S tooling with tang arbors a while back, I set them up in the lathe drilled a pilot hole through the center drilled hole in the tang to keep it in line, cut the tang off then drilled to tap size and tap 1/2-13 for my mill. It worked ok for me.



This is exactly the kind of posting I wanted to see or hear about here. Others success or knowlege of success in an undertaking such as the one I am contemplating.

Well, after discussing this with the machine shop foreman at work I have decided to buy the tang type and cutoff the tangs and drill and tap them for a drawbar. The foreman agreed with my thoughts that the holders are likely only surface hardened and will likely respond well to drilling and tapping for drawbar use. Thanks to the guys that replied.


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## Chuck K (Apr 20, 2013)

I would agree with your assumption.  I have cut the tangs off morse taper adaptors and they weren't hardened.  What I have noticed in the past when looking in tool catalogs is that if they are hardened and ground they state it in the ad and charge accordingly for it.  I'd be surprised if you have any problem tapping them.

Chuck

I should have actually looked at the link you posted.  I still agree that they won't be hardened deep enough to cause a problem tapping them.


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## Uncle Buck (Apr 21, 2013)

Chuck K said:


> I would agree with your assumption. I have cut the tangs off morse taper adaptors and they weren't hardened. What I have noticed in the past when looking in tool catalogs is that if they are hardened and ground they state it in the ad and charge accordingly for it. I'd be surprised if you have any problem tapping them.
> 
> Chuck
> 
> I should have actually looked at the link you posted. I still agree that they won't be hardened deep enough to cause a problem tapping them.



I think this is going to prove a very nice accessory for my little machine. I already have about a 1/2" dozen shell mills to fit the largest holder. Those mills are great quality old USA made that were surplus.


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