Boring bar holder?

[raferguson]

I have some 3/8" shank boring bars, but no holder for them. LMS has a holder for 1/2" shank boring bars, but not 3/8" shank; I have an email from them confirming this. Their holder is simply a square piece of bar with a hole bored in it, and a slit so that the screws in the tool holder will hold the bar tightly.

I have identified three options (happy to consider other options).

1. Buy a boring bar holder, but where? I did some looking on google, did not find anything.

2. Make a boring bar holder, probably patterned on the 1/2" LMS holder.

3. Make a sleeve to fit inside the 1/2" holder that I have.

Options 2 and 3 imply some machining, and then cutting a slit. I suppose that I could cut the slit with a hacksaw, or bandsaw, or even a jeweler's saw. I do not have any slitting tools for my mill-drill, and I would need to buy an angle vise or table, so that sounds complicated.

I have a basic mini-lathe, no fancy holder. I have a more or less typical mill-drill, not a mini. I consider myself a beginner, but not a total beginner.

What do you suggest?

Richard

 

[benmychree]

The Aloris type 2 holder with the vee cut on the bottom of the slot works just fine for all types of small boring bars.

 

[Jim F]

The Aloris type 2 holder with the vee cut on the bottom of the slot works just fine for all types of small boring bars.

This.

 

[benmychree]

This.

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[Firstram]

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I'm sure he was reiterating your suggestion!

 

[mmcmdl]

Hard to give you an answer as we don't know what post you have , or even if you own a post . Can you give us a little more info. ?

 

[bill stupak]

A boring bar can be held in a regular tool holder.

 

[compact8]

All boring bars I have come across have two flat surfaces on the opposite side of each other. Just clamp it to the tool holder in the usual way.

 

[raferguson]

Thanks to all. I will try to use the boring bar without a holder by tightening the screws, and see how that works.

 

[mikey]

Richard, the answer to this one depends on how accurate you need to be.

• If you just need to bore a hole within a few thou then use a number 102 holder, the one that has the V. It will work just fine. Sleeves like the LMS variety also fall into this category.
• If you need to bore to tight tolerances, in the tenths, then rigidity is critical and that 102 holder will not provide the support you need. Here you need a holder that encloses the bar and holds it rigidly. The best of these is the Aloris 4D and you would need to make reducing sleeves to fit your smaller bars. That requires machining the sleeves and slitting the slots to make the sleeves work but it it the best solution I know of.