best machine tools for lathe

[Neil WyattModerator @neilwyatt]

Posted by SillyOldDuffer on 13/03/2018 10:10:57:

Posted by Neil Wyatt on 11/03/2018 20:04:36:

Most carbide tipped tools are supplied as unground blanks.

Most suppliers don't state this.

Most purchasers don't realise this.

Hence most users think they are crap because they are trying to cut using tools with negative front clearance, which is like trying to thread a rope through a needle…

Neil

Well I never. Is that true of the sets though?

Absolutely, this example shows how the carbide is just brazed in place and needs clearance grinding on it. Don't be misled by the slope on top of the shank, the base of the tool is set flat.

Edited By Neil Wyatt on 13/03/2018 10:52:40

[SillyOldDufferModerator @sillyoldduffer]

Posted by Neil Wyatt on 13/03/2018 10:51:59:

Posted by SillyOldDuffer on 13/03/2018 10:10:57:

Posted by Neil Wyatt on 11/03/2018 20:04:36:

Most carbide tipped tools are supplied as unground blanks.

Most suppliers don't state this.

Most purchasers don't realise this.

Hence most users think they are crap because they are trying to cut using tools with negative front clearance, which is like trying to thread a rope through a needle…

Neil

Well I never. Is that true of the sets though?

Absolutely …

That's amazing, quite unexpected. Never seen that important little detail mentioned elsewhere. I assumed new tools would be ready to go. Gets my vote for the 'Tip of the Year Competition' !

Thanks,

Dave

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Neil Wyatt on 13/03/2018 10:51:59:

… this example shows how the carbide is just brazed in place and needs clearance grinding on it. Don't be misled by the slope on top of the shank, the base of the tool is set flat.

.

It looks like the base of the tool would need grinding flat before it would sit properly in any known tool-holder !!

… Is this really what people are buying these days ?

MichaelG.

[JasonBModerator @jasonb]

I've never had a problem getting the brazed ones I have bought to cut straight out of the box as they say. Still use them for certain jobs

[Howard LewisParticipant @howardlewis46836]

I use a holder from Greenwood Tools, that uses the normally unused 100 degree corners on CCMT0602 tips, (when the 80 degree corners become worn in the Boring bar), for roughing.

The tips usually come from JB Cutting Tools.

For finishing I use a home made Tangential Tool Holder for 5/16 HSS. At the risk of boasting, (pride will come before a fall) when just sharpened, this will often take a 0.0005" cut on mild steel.

Howard

[Neil WyattModerator @neilwyatt]

Posted by Michael Gilligan on 13/03/2018 18:40:50:

Posted by Neil Wyatt on 13/03/2018 10:51:59:

… this example shows how the carbide is just brazed in place and needs clearance grinding on it. Don't be misled by the slope on top of the shank, the base of the tool is set flat.

.

It looks like the base of the tool would need grinding flat before it would sit properly in any known tool-holder !!

… Is this really what people are buying these days ?

MichaelG.

No the opposite. Its just ground under the edges of the tip, to stop any distortion from when the tip was forged stopping it lying flat. The main shank is dead flat all along.

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Neil Wyatt on 16/03/2018 15:59:50:

Posted by Michael Gilligan on 13/03/2018 18:40:50:

It looks like the base of the tool would need grinding flat before it would sit properly in any known tool-holder !!

No the opposite. Its just ground under the edges of the tip, to stop any distortion from when the tip was forged stopping it lying flat. The main shank is dead flat all along.

.

Glad to hear it, Neil

Note: I did, cautiously, use the phrase "It looks like" … [which it still does]

MichaelG.

[Sub MandrelParticipant @submandrel]

Posted by Michael Gilligan on 16/03/2018 18:00:12:

Glad to hear it, Neil

Note: I did, cautiously, use the phrase "It looks like" … [which it still does]

MichaelG.

If it was my old set, you would probably have been right..

I'm not paying for a copy of DIN4980 to find out exactly what the specification is. I note that while some beautifully finished brazed tip tooling costs more than the typical set used by hobbyists, some 'professional supplies' sites sell supposedly 'precision ground' DIN4980 tools that have the entire carbide tip completely covered in paint…

Neil

[Sub MandrelParticipant @submandrel]

There's a good article in another place

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