Purchasing right boring bar holder for existing lathe tool post

[Omni-impotent]

Hello all! First time poster here.

I want to be able to hold a 1/2" diameter shank boring bar on my existing lathe tool post but don't know how to make sure the holder fits.

The Tool Post we have is a Phase II 250-111 (see attached image).
"Phase II
9 to 12 Inch Lathe Swing, Wedge Type Quick Change Tool Post
3-7/8 Inch Tool Post Height, Series 100, 4-11/16 Inch Overall Height"

The boring bars have 1/2" shank diameter. I'm hoping to get a different brand for the tool holder because it is cheaper.
There are two I'm considering:
(1) Value Collection - Tool Post Holders Series: AXA Tool Post Holder Number: 4
(Tool Post Holders; Series: AXA ; Tool Post Holder Number: 4 ; Tool Post Holder Type: Boring, Turning & Facing Holder ; Lathe Swing (Inch): 12 & Under ; Through Coolant: No)

(2) Value Collection - Tool Post Holders Series: BXA Tool Post Holder Number: 2
(Tool Post Holders; Series: BXA ; Tool Post Holder Number: 2 ; Tool Post Holder Type: Boring, Turning & Facing Holder; Lathe Swing (Inch): 10 to 15 ; Through Coolant: No)

How do I know which one will fit? I'm confused by the OXA or AXA as I don't see that specified in the description of the Tool Post.

Thanks in advance

 

[MrWhoopee]

250-xxx is the AXA series. A 250-102 is a standard tool holder with a groove in the bottom. I can be used for turning tools and a boring bar.



250-104 is strictly a boring bar holder, it comes with 19mm/3/4 in. bore and a sleeve that reduces to 16mm/5/8 in. You would have to buy or make a 1/2 in. sleeve.



HTH

 

[darkzero]

Specifically you need 250-1xx series holders which are AXA size. 250-2xx is BXA.

 

[MrWhoopee]

Specifically you need 250-1xx series holders which are AXA size. 250-2xx is BXA.

Thanks for clarifying this.

 

[Omni-impotent]

Thank you! What an invaluable piece of information. While I'm at it, I actually have one more question.

The boring bars I have are in the attached pic. I want to use them on a lathe. Someone told me that these are for boring heads for a mill but "they'll work".

What's the difference between the two?

 

[darkzero]

I'm confused by the OXA or AXA as I don't see that specified in the description of the Tool Post

In case you wanted to know....

The letter designations were created by Aloris except 0XA which is not an Aloris standard. IIRC 0XA size was created by LittleMachineShop & Tormach which is smaller than AXA. Imports copied the sizes & use the 250-XXX designations.

For the tool posts:

Wedge Type:
AXA = 250-111
BXA = 250-222
CXA = 250-333
CA = 250-444
DA = 250-555

Piston Type:
AX = 250-100
BX = 250-200
CX = 250-300
C = 250-400

 

[MrWhoopee]

Those boring bars will work for either a lathe or mill. They will probably require significant grinding to work properly in a boring head on a mill.

 

[darkzero]

Thank you! What an invaluable piece of information. While I'm at it, I actually have one more question.

The boring bars I have are in the attached pic. I want to use them on a lathe. Someone told me that these are for boring heads for a mill but "they'll work".

What's the difference between the two?

The boring bar sets for use in boring heads will usually have all the same size diameter & length shanks for the set. 1/2" dia being the most common. Yes you can use them. Lathe boring bars typically have shanks that are the same diameter for the full length of the bar. This allows you shorten up or extend the length when mounted.

Often those economy brazed carbide sets aren't ground well from the factory (geometry). So if you find that they are not performing well you'll need to regrind the geometry & most likely put a nose radius on them. They tend to come with too sharp of a nose radius & won't last long cutting like that.

 

[darkzero]

Hello all! First time poster here.

Oh & Welcome to H-M!

 

[mikey]

Yes, welcome to HM.

I have an opinion on boring bar holders that differs somewhat from the typical tool holders like the 250-102 or the type that uses cotters to pin the bar. I think you will have a much better boring experience if you go and buy an Aloris AXA-4D. This holder surrounds, supports and solidly holds the boring bar shank better than almost any other tool holder. The boring bar holder is more important than the bar itself, at least in my opinion, and the 4D is worth the cost. The 4D has a 3/4" bore so you will need to make reducing sleeves to fit your 1/2" bars but that is not difficult to do.

The set you have is a HSS cobalt set. They work well in a boring head on the mill but can also be used on the lathe. Just keep in mind that the theoretical depth they can bore to is 4 times the diameter of the smallest part of the shank up near the head. Cobalt bars like yours will bore very well within their depth limits and will often finish better than most carbide tools. They can be easily sharpened by using a diamond hone to lightly flatten the end of the head and a very light dressing on the top flat.