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Boring head connection type?

ManualEd

Stainless
Joined
Oct 13, 2014
Location
Kelowna, Canada
I despise the shitty chinese dovetail style boring heads for my milling machine.

Fleabay has a few nice D'Andrea boring heads, and some Big Kaiser boring heads that all appear to have the same shank connection.
However, I need an NMTB 40 holder for my mill, not a Cat 40 that most come with (power drawbar/drawbar has some funky spline on the end of it so I can't change the drawbar easily) .

Edit : GAH, I couldn't have made it more unclear if I tried.

What the hell is that connection called, with the round shank with a hole in it?
Are they a standard connection, or is it a case of "the same but different" that manufacturers like to play?


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It's easy enough to hard turn or grind your own.
I've done it for a few boring heads including a Wohly, Tree, and a Precision for my NMTB30/MM30 spindle.
Due to none of them taking standard boring shank threads.

Last i looked, the NMTB40's were even more common than 30's on eBay. Though most are from China....

Noting that i have and use the heads above + a few more American made, my only problem with the simple chinese dovetail heads you mention is that you can't read the fuzzy electro-printed tiny number dials. The heads themselves work pretty well.

Can you link to a picture of one with the "problem" shank?
Can the "feature" you don't need just be ground off?

smt
 
Last i looked, the NMTB40's were even more common than 30's on eBay. Though most are from China....
I can understand if he doesn't like the cheesy chinese dovetail style. I actually like the devlieg type,

IMG_8362.jpg

haven't tried the balanced type but they look interesting ...

IMG_8363.jpg

or maybe there's a couple of concentric bores, he wants to save a few seconds on tool changes

IMG_8358.jpg

or maybe bore and face in one op ...

IMG_8351.jpg

my only problem with the simple chinese dovetail heads you mention is that you can't read the fuzzy electro-printed tiny number dials.

You're supposed to use the laser presetter :)

IMG_8361.jpg
 
As I understood the question OP is asking what the shanks on the boring heads are called so he can get the correct NMBT 40 holder.
See red circles in picture.
Thats my bad for a terrible post description.
Thats what I'm trying to find out. Lots of boring heads have a connection that looks the same, but I have a feeling they aren't quite standardized.
 
Thats what I'm trying to find out. Lots of boring heads have a connection that looks the same, but I have a feeling they aren't quite standardized.

Ah ! Looks like by accident I put up a photo of what you are looking for. Invoice will be in the mail :)

With luck someone will know the official name. I just call them "round shank with the locating divot" :D
 
I have 4 different brands. All are dramatically different, not even close to fitting together. Diameters are different, hardware is different and in different locations.
If you get just a head, you usually can hold it with a collet of the proper size, sometimes there's a locator on the face that interferes.
 
If I understand your question, the Kaiser model is called the KA connection. The NTMB models are;

NTMB40 to KAB4 P/N 11.321.541
NTMB40 to KAB5 P/N 11.321.551
NTMB40 to KAB6 P/N 11.321.562

The KA spec determines which Kaiser head will fit and by extension, what range of bores one can do with it.
Each Kaiser head has three insert holders which change the range of bores.

The 310.411 head will do 1.61-2.91
The 310.511 head will do 2.09-3.74
The 310.611 head will do 2.68-5.91

There are extensions for all of those which will give one a different depth range.
I'm a huge fan of the Kaiser stuff, been using it for decades. I worked in a jig boring facility in my younger years and was assigned the job of deciding which brand of boring heads to get while upgrading for the shop. Kaiser beat out all the others at the time, they really nailed simplicity and accuracy. I now have my own set, and can attest to the quality of these. (not affiliated in any way with any tool supplier or manufacturer)

Hope that helps
 
A stupid little question. Is there ever a reason to run a boring head in reverse. I do not think so and many smaller heads are screwed onto a shank aren't they?
Bill D
 








 
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