View Full Version : set screws for 100-size quick change tool post

01-22-2006, 04:07 PM
Once again I humbly call upon the collective experience and wisdom of the board here. I've got a 100-size (AXA?) piston type quick change tool post system. Yeah, I should probably have more than 5 tool blocks, but that's the situation right now. I change the cutters in and out of two of the blocks I have most often. When I got them, one or two of the set screws in the tool blocks had been a little "boogered up" by the previous owner. Of course, with continued use, it's gotten a little worse. No problem, then - I'll replace them. "Hmmm. What's the big hurry there, son?"

Right. I measured them with calipers and a thread pitch gage. They appear to be 5/16-20 by 1/2" long. That's right, 5/16-20. Not 5/16-18 or 5/16-24, like everyone carries in stock. Yeeeesh. Reminds me of the recent thread (no pun) here about Starrett tools and strange thread sizes on them. Is this another such case?

Certainly one of you has run into this problem, right? Any ideas on where to find these things? Getting a Watts Brothers hex drill and cutting my own threads may be a bit too much trouble. http://bbs.homeshopmachinist.net//wink.gif

01-22-2006, 04:14 PM
Metric,silly millimeters.
8x.5 IIRC

The tame Wolf !

[This message has been edited by IOWOLF (edited 01-22-2006).]

01-22-2006, 04:17 PM
Great. I wish I had a metric thread pitch gage. Oh well, I guess it's time...

Anyone know offhand what metric size looks like 5/16-20??

Thanks in advance. I'm going back down in the shop to check this out further.


01-22-2006, 04:20 PM
8mm x 1.25 pitch,common for metric.

01-22-2006, 04:23 PM
Wire - -
Just a suggestion.
What you describe is very close to M8-1.25
Hth Ag

01-22-2006, 05:37 PM
<font face="Verdana, Arial" size="2">Originally posted by Wirecutter:
They appear to be 5/16-20 by 1/2" long. That's right, 5/16-20. Not 5/16-18 or 5/16-24, like everyone carries in stock. Yeeeesh.</font>

That's a good question. I looked at my own tool holders. I have 19 Aloris AXA's. Their screws average .3065" diam X 18 tpi. 5/16 is actually decimal .3125 which is close enough to 5/16 I suppose.
I have 3 Phase II holders in AXA. Their screws are metric at 7.89mm (close enough to 8mm as they are a sloppy fit) with a 1.25 mm pitch.
The Aloris screws would not fit into the Phase II holes, and the Phase II would not fit into the Aloris.
A 5/16 X 18 tpi bolt would NOT fit into the Phase II holder beyond 1 1/2 turns, but it fits into the Aloris with a very snug fit. The snugness could be from debris in the threads of the Aloris.
Seeing as how I have to replace a screw in a Phase II, I would just tap it with a 5/16 tap, and replace the rest of the screws so they are the same.
Good question. Which do you have?

[This message has been edited by YankeeMetallic (edited 01-22-2006).]

01-22-2006, 06:14 PM
I have the 200 series toolpost. They are the Chinese "metric" which does not really match anything. I was able to retap to 5/16"-18 by using a new tap and plenty of Tap Magic. Go easy and back the tap up frequently.

01-22-2006, 06:20 PM
I pulled out a Phase II parts list for the 100 series. It says M8 - 1.25 x 20 for the turning holder.