Tangential tooling

[JasonBModerator @jasonb]

Not one that I’m supposed to post on here but easy enough to find on the net.

I could also say that the inserts are useful when you what various internal radii and the **GT ones are also good on many plastics. 😉

[JasonB]

On JasonB Said:

I could not see a price for the replacement HSS blanks but you can get a box of 10 inserts to drop onto your doormat for £4-5 so that is 40 sharp usable corners. Similar cost for a holder. Diamond holder is £92 inc delivery so possibly cheaper over time as you should be able to get quite a few sharpenings out of a bit of HSS. That is provided you are not cutting chilled castings which will take the edge off your HSS rather quickly.

Insert is probably more practical when working small diameters with tailstock support. And you can use the inserts in your boring bars so saves having to buy both.

You can probably gues from above that I have not been tempted to buy or even make one.

I’m almost all carbide now, probably over 95% of my turning and at least 80% of my milling is now done with insert facemills or solid carbide, that will go up as I work through what HSS cutters I have that are still usable and replace with carbide. Drilling and reaming still HSS.

I’ve wanted to try one if the tangential holders ever since I found out about them. But like you, most of my cutting is done with carbide. I’d say about 90% for the lathe but less so so on the mill. Maybe 40-50%. I can’t be bothered with the mess and time needed to grind HSS. On top of that, theres absolutely no way I could grind a tip as accurately as carbide.

[bernard towersParticipant @bernardtowers37738]

When you say grind your tip accurately what exactly do you mean?. The basic angles are very forgiving, most of the problems are when grinding screwcutting tools but that comes with practice and a few jigs.

[Howard LewisParticipant @howardlewis46836]

Carbide tips are marvellous if the material is hard, and can produce excellent finishes.

But are less tolerant of careless handling or interrupted cuts.

The advantage of tangential tools is that the HSS toolbit can be sharpened easily, when the shops are closed for the weekend, and can be ground to a specific shape for a particular job.

Horses for courses.

Both have their uses.

Howard

[VicParticipant @vic]

Yes, agreed Howard. I started with the small carbide inserts aimed at hobbyists – next to useless, they don’t last. I now mostly use TNMG16’s if I can, they’re much more durable. A bit more expensive but you get six cutting tips.

[Neil LickfoldParticipant @neillickfold44316]

Carbide has moved a long way in the last few years.

There are now grades of carbide that handle interrupted cutting on steel even at 58Rc.  But need specific conditions, like slow feedrates, 0.05mm-0.06mm/rev and small cuts, upto 0.4mm depth of cut.  Even with softer material , a slow feedrate of 0.05mm-0.06mm /rev and around 1mm depth of cut works just great.

The most damage to inserts is cutting to the centre when facing. So to avoid that, either relieve the centre with a spot drill or small endmill, ball mill, or in my case now, I use the tangential tool for the end facing.

With a small mounted point or diamond bur , can add a small relief / chip breaker behind the top face cutting edge can work very well for softer materials like Ali and MS. Not recommended for materials that can pull the tool into the material like brass or some plastics.

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