Internal threading, sizing the bar to the hole

[mikey]

I would call the Micro 100 tech line. Tell them you need to cut 8tpi, 2" bore depth, right hand thread. They will tell you which specific bar to get.

 

[WobblyHand]

I would call the Micro 100 tech line. Tell them you need to cut 8tpi, 2" bore depth, right hand thread. They will tell you which specific bar to get.

Since they are not open now, thought I would look in their catalog. The only thing I see that is close is the IT-4902000. 8-24 TPI. It has L2 = 2" bore depth. It is also only L1 = 3" long. To me that means the part one grabs on is only 1" long. What does one use to hold the bar? Shank is 1/2" diameter.

Annoyingly, it is a stock photo, which has the proportion of L2 = 1/3 L1. In actuality, the proportion is L2 = 2/3 L1. So what one gets doesn't look like the picture. https://www.micro100.com/products/tool-details-it-4902000#moreDimensions

 

[mikey]

I usually call and get a specific model number, then go find it on ebay or Amazon. Maybe try in the morning?

 

[mmcmdl]

Here's a choice of bars you can use , depending on if you want to thread in or out . Top is a Manchester 1/2 bar which will fit in a AXA-1 or 1/2" BB holder . You thread in with it .

The lower is a Kennemetal top knotch for a 3/4" BB holder that you would thread in reverse and away from the chuck . Both will do the job depending on which you feel more comfortable doing . I have the correct insets for both btw .

The Aloris P4 blade is for your OD thread as you know .

 

[WobblyHand]

Here's a choice of bars you can use , depending on if you want to thread in or out . Top is a Manchester 1/2 bar which will fit in a AXA-1 or 1/2" BB holder . You thread in with it .

The lower is a Kennemetal top knotch for a 3/4" BB holder that you would thread in reverse and away from the chuck . Both will do the job depending on which you feel more comfortable doing . I have the correct insets for both btw .

The Aloris P4 blade is for your OD thread as you know .

Since I'm momentarily tailstockless, due to quill spin, I would use the Kennametal 3/4" bar going out. Can't make the 1/2"/3/4" sleeve at the moment. My AXA-4 is 3/4". Rather use an AXA4 than a AXA2 or 1.

If threading outward, the compound is 30 degrees toward the chuck? So the advancement of the bit is towards the tailstock, correct?

 

[mmcmdl]

The 1/2" Manchester will fit in a regular axa-1 turning holder so no need for a sleeve .

Edit . OK , just saw the part you would rather use the BB holder . I'll pack them up and get them out ASAP !

 

[WobblyHand]

The 1/2" Manchester will fit in a regular axa-1 turning holder so no need for a sleeve .

Rather use the 3/4, for this. Stiffer is better. 8 pitch will want to chatter, I'd think. Bigger bar is stiffer.

 

[mmcmdl]

Yep , saw it and edited my post above.

 

[mmcmdl]

These will be coming your way in an hour . There is a new insert in the bar and one taped to the bar . Good luck !

I'll PM you the tracking info .

 

[mmcmdl]

On their way .