insert for boring bar

[hdwrench1]

Hello Everyone
I have to enlarge a hole in a hardened gear for a transmission.
The hole is for a double lip seal.
I am concerned that because the gear is hardened I may have a hard time cutting it.
I am using a boring bar using CCMT style inserts
Does anyone have any suggestions for me before I start

Thank you
Wayne

 

[Chitownmachine]

It all depends on how hard it is. I cut hardened material all the time at work with carbide and ceramic inserts. Do you know what the Rc is on the gear? Also go slow and feel out the material....when in doubt slow it down!

 

[hdwrench1]

I don't know the RC but it is the 4th gear from a Harley 4 speed transmission.
I looked for ceramic inserts at KBC tools but they don't carry them.

thanks
Wayne

 

[websterz]

If you can scratch the gear bore with a file you can cut it with carbide.

 

[hdwrench1]

Thanks Websterz,
I have to go to to work tomorrow so I'll try that first thing

Thanks a million
Wayne

 

[lensman57]

Hello Everyone
I have to enlarge a hole in a hardened gear for a transmission.
The hole is for a double lip seal.
I am concerned that because the gear is hardened I may have a hard time cutting it.
I am using a boring bar using CCMT style inserts
Does anyone have any suggestions for me before I start

Thank you
Wayne

Hi,
Depends on the hardness of the steel and the Grade of the CCMT, if you could find the time to browse through the on line catalogues of Kennametal, Seco or Sandvik Coromant you will get some idea of the suitable grades and information about the cutting speed, etc but I warn you that it is a mindfield out there.

Good luck and best regards,

A.G

 

[Swede]

Carbide is amazing stuff, and I've used it to cut high speed steel, so there's a strong chance good carbide tooling will do the trick with your gear. Good luck!

 

[prof65]

If nothing else works you can use a little tool-post grinder, slow but effective.

 

[Darren English]

I quite often cut hardened steel with CCMT tips. They work well, just go slow, about 15 meters per minute (400 revs for 7/16 dia) if not slower.
They will lose their edge quickly, if this is a one off you will be fine.
If you have any problems (vibration or finish) just slow down the revs.