Boring small holes smooth

[Brad93]

Has anyone tried these miniature carbide boring bars? Similar to the Micro100 tools.

I could of done with boring a 13mm hole out earlier, nice and smooth plain bearing finish but don’t have a 13mm reamer.

£13 seems cheap enough.

Second question. How on earth do you hold a boring bar this small.

 

[pressbrake1]

To hold it put a block of steel in the tool post then use the lathe to drill and ream to suit . That will put it dead on centre height.
To hold it pinch bolts or preferably split it so it clamps

 

[Seadog]

It depends on the method you use to hold your other bars. A reducing sleeve would seem like the obvious way.

 

[northwest]

Be very careful Brad, some of them have a lovely round shank (the Iscar ones) and others are oval and you need the dedicated holder.I have bought them in the past from a bloke called CNCpoorboy on ebay at a very good price. I just send him a message.

 

[Hood]

Often the shanks of these mini boring bars are not round so make sure any you buy are or if not you can get the appropriate holder.
I have the WNT version of them and they are brilliant.

 

[Hood]

BTW that set pictured is about £110 plus VAT I think.

 

[Screwdriver]

If push comes to shove, weld/braze it onto a regular tool shank.

 

[Hood]

Does carbide weld?

 

[mtt.tr]

Just to cause upset hss anyone?

 

[slim_boy_fat]

Collet chuck?

 

[mtt.tr]

Does carbide weld?

Super glue and duct tape

 

[Hood]

Just to cause upset hss anyone?

Lots of these are HSS, it is about the only HSS I use nowadays although I do have a DNMG HSS insert somewhere

 

[pressbrake1]

Does carbide weld?

No hence use of sintering material

 

[Hood]

Super glue and duct tape

Spoken like a true builder

 

[mtt.tr]

Spoken like a true builder

At heart im a man of hide glue

 

[Hood]

At heart im a man of hide glue

I had heard but was unsure if true.

 

[mtt.tr]

I had heard but was unsure if true.

We all are, though some are made from straw?

Anyhow builders use expanding foam

 

[Hood]

....
Anyhow builders use expanding foam

Just the more modern ones

 

[Kram]

For a 13mm hole, Id use an S07K-SCLCR06, they are cheap, ccmt06 inserts and a min hole size about 8mm.
www.ebay.co.uk/itm/S07K-SCLCR06-7x125mm-Lathe-Internal-Boring-Bar-Turning-Tool-Holder-For-CCMT0602/293134555726

PH Horn are the ones to avoid, unless you like the challenge of making holders

Its quite a simple holder. 5mm hole, 2.5mm hole and mill between. The difficult bit is finding an extra long series 2.5mm endmill, and drill bit. I did chip the big one and needs regrinding

They are excellent. HSS in that size flaps around like a spring this hardly moves.

PH Horn inserts are always a funny shape that is difficult to make a holder for, and holders not cheap.

 

[brightspark]

Does carbide weld?

you can braze it easily enough