# Tool Post



## Elmo (Nov 27, 2015)

Some more dumb questions. My experience with tool posts is limited to the lantern type. What is the difference between the axa, bxa, and cxa tool posts?  Will the tool holders interchange between them? Finally how can I determine which one is on my Emco 13" lathe. It is an Armstrong and appears to be a piston type. The tag has a tool number OC-4. 
  Elmo


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## middle.road (Nov 27, 2015)

Are there any other numbers on it or the holders? And is the 'O' possibly a 'Q'?
I'm not having any luck search, but then again I'm only on my second cup of coffee...
Any chance you might have some pictures?


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## planeflyer21 (Nov 27, 2015)

Elmo said:


> *1:* What is the difference between the axa, bxa, and cxa tool posts?  *2:* Will the tool holders interchange between them? Finally how can I determine which one is on my Emco 13" lathe. It is an Armstrong and appears to be a piston type. The tag has a tool number OC-4.
> Elmo



1: Size and capacity of the tool holders.  In general:  AXA=6"-12", BXA=12"-15", CXA=13"-18" lathe sizes.

2: There is some interchangeability, with some adapters also available to use the smaller sized tool holders with the larger sized tool posts.

Check with your favorite suppliers.


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## Elmo (Nov 27, 2015)

I went out and took othese.


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## RJSakowski (Nov 27, 2015)

It is important to be able to get your cutting edge at or below the centerline of the lathe.  

Measure the distance from the compound  to the lathe center line.  The distance from the base of the QCTP holder to the top of the tool holder slot should be less than this measurement.  For the Aloris tool holders, the measurements are 15/16", 1-1/8", and 1-7/16" for type 1 AXA, BXA, and CXA  holders, respectively in order to use the sized tool bit.  You can use smaller bits to bring the cutting edge lower but this compromises the utility of the QCTP.  The dimensions of QCTP tool holders vary  between different manufacturers.  If you look in the Travers, Enco, or MSC catalogs the tool holder dimensions are usually published.


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## chips&more (Nov 27, 2015)

According to info on the net (not from my knowledge). Your QC-4 is interchangeable with the Aloris AXA holders and it’s clones…Dave


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## tomh (Nov 27, 2015)

elmo
Does any of your numbers correspond with these. If so it should be a AXA
Turning, facing and boring tool holder 4B-QC / 81-041
Cut-off tool holder 4D-QC / 81-081
Knurling tool holder 4E-QC / 81-101
Heavy duty boring tool holder (3/4" bar) 4G1-QC / 81-159
Threading tool holder 4J-QC / 81-121

 AXA  #'s     will be 250-1xx
BXA #'s will be 250-2xx


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## RJSakowski (Nov 27, 2015)

I had seen a post on another forum that the Aloris tool holders wouldn't fit the Armstrong QCTP but no personal experience.

The Shars site has drawings w/ dimensions for the tool holders.  you should be able to determine suitability from those drawings.


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## Wreck™Wreck (Nov 27, 2015)

Each letter combination denotes a size of toolpost, Aloris makes the data easily available here in their catalog http://www.aloris.com/wp-content/uploads/AlorisCatalog_April.pdf. 

Aloris was one of the first Companies to push the concept widely hence most manufacturers have adopted these dimensions when making compatible tool blocks and posts, Dorian Tool and Phase II for example. This has enabled hobbyists and maintenance departments across the land to purchase low priced yet compatible tooling and holders.

Do not expect Hardinge or other high end systems of tool holding to work with these at all.


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## Elmo (Nov 27, 2015)

Thanks guys! That is enough info to get me started.
  Elmo


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## Jeedub (Mar 16, 2022)

I just got myself a Busy Bee B244 lathe. It has the original screw down type of tool post. I picked somewhere a number of Armstrong tool holders that all start with 81-###. From What I see here I need a AXA toolpost to utilize these. Correct?


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