Techniks ISO30-ER40 Chuck Will Not Fit the Spindle/Sharp LMV Mill

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I am new to the ISO 30, Spindle.
I have a handful of the ISO 30 tool holders for specific Imperial sizes.
It was mentioned on this forum to just get a good set of ER40 collets. I thought that was a much better option.
The ER40 chuck I bought is of high quality, the collets fit and lock up very nicely.But, the ISO 30-ER40 chuck will not clear the locking lugs on the spindle.
I am hoping I am missing a locking ring adapter of some sort?
Please see the pics.
Thank you,


I thought of that but I can't seem to find one that has the lug cut outs. CAT 40 yes.
What if I removed the lugs? Too Mickey Mouse?
The weakest link will be the taper. The collets lock up very well.
These mills came with R8 or ISO 30.
If worse came to worse I guess I could buy a R8 spindle if it wasn't cost prohibitive.
Hmm, the literature published back when it was made showed two spindle options.
R8 and ISO 30.
I assumed ISO 30 was correct because the tool holders that came with the used mill were all ISO 30 and fit properly.
By properly, I mean they fit up into the lugs and the draw bar pulls them in tight.
I don't know enough about Cat 30 or ISO 30.
Is there a way of defining that spindle?
Please excuse my ignorance, my Bridgeport was R8. This is my first time at bat with ISO/CAT 30. Isn't there also BT30?
It's a Sharp LMV. I'll see what I can find. I will also look at illustrations of NST 30.
I found literature that showed ISO 30.
Thanks for checking. I have some home work to do.
Hi Jeff: I have two mills that use 30 taper like the one you have, I think that originally it was known as NMTB 30 (National Machine Tool Builders), which uses the two driving lugs and a drawbar; I found all my adaptors on e bay, including collet adaptors, all used and in good condition for not much money. It seems that ISO (International Standards Organization) 30 taper and NMTB 30 are the same animal, Cat 30 has a retention vee cut on the flange.
NMTB 30 and the Ericson QC are the same except the flange is smaller on the Ericson.
NMTB 30 on the left, flange measuring 1.969"
Ericson on the right measures 1.812"
I've used NMTB 30's in the Ericson QC system by turning down the flange. Although the Ericson system is labeled "quick change", it's not faster than a power drawbar. If you use a power drawbar, the flange size doesn't matter.
The reason that I like the 30 taper as apposed to the R-8 is that it is easier to remove and exchange tools without having to lower the knee or move the job laterally due to the longer length of the R-8 and to taper of the 30 tools allowing the adaptors to be lowered and tilted out.
Thank you John,
I have not been able to verify the difference between the 30 taper configurations.
I’ll check it out.
You would need to cut notches in the flange of that collet chuck and make a longer draw bar to use it on your mill. The taper will be the same
I ordered a NST 30 ER40 chuck.
The collets will be fine. I like the way the ER series locks up with very little TIR.
You would need to cut notches in the flange of that collet chuck and make a longer draw bar to use it on your mill. The taper will be the same
I think I will just return it.
As benmychree says above, NMTB30 and ISO30 (DIN2080) are the same, although the drawbar thread will be imperial for the NMTB (USA) and metric for the ISO (Europe etc). Being intended for use with a drawbar, they have the parallel shank at the narrow end.

The other tools that have no parallel shank are designed to take pullstuds instead of a drawbar. These are BT30 etc although you can use them in a drawbar machine if you simply use a longer drawbar. They also have the groove in the largest diameter, as they are designed to work with an auto toolchanger (ATC - tend to go hand in hand with pullstuds). With a power drawbar, most likely you don't really need the drive dogs anyway, so you could just remove them if they cause problems.

Seems you were sold BT30 tooling although it was (wrongly) described as ISO30. Took me a while to figure out the various flavours of 30 taper tooling - you are not alone!

On my machine I have a pullstud system and use both ISO30 and BT30. The solution was to have longer pullstuds for the BT30 tooling. That gave me a better choice of 30 taper tooling which isn't as widely available as 40 and 50 taper.

On my bigger machine which takes ISO40 tooling, I acquired some cheap BT40 tooling and simply TIG welded the parallel shank to convert it to ISO40. Works well enough for the likes of me but 40 tooling is pretty cheap anyway so for accurate work I buy the proper ISO40 tools.

I'm in the UK and get most of my toolholders from Cutwel. The 40 taper tooling is about half the price of the 30 tools (£20 vs £40). https://www.cutwel.co.uk/tool-holding/spindle-tooling/din2080-iso30iso40iso50/iso30-end-mill-holders-1 Unfortunately, I suspect they may not ship out of the UK, based on my experience when I loved in Canada.
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