90 degree indexable insert for chamfers.

Morning, I'm looking for a carbide insert tool that is (or almost) 90 degrees with the cutting edge pointing towards the work. It's to use as a chamfer tool, internal and external.

i currently use a V shape piece of HSS, but I'd rather use something with a carbide insert.

Thanks,

Chris,

How about one of these?

HTH

Rod

If you want to use the same tool for internal and esternal chamfers at 45deg then you need one that takes a square insert, Have a look at MSC they do several that fit the bill. I don't think any of our usual ME suppliers do ones that can do more than one chamfer as the 85/95 rhombic insers only give 40deg chamfer on teh opposite edge.

J

Edited By JasonB on 07/11/2014 13:24:53

Thanks for the replies.

Your right ideally is like one with a square insert at 45 degrees to the work.

I had a quick look at the MSC website but could only see carbide holders for around £60 which is too much for me

I'm wondering if u should made my own now!

Internal chamfers are tricky with the side of the tool due to restrictions in side clearance, prefer to off set the compound slide to 45 degrees and use that with a boring bar. That said it is dependant on diameter.

Bob

The piece of 10mm HSS I made my last one from was fine for internal chamfer down to around 12mm bores, which is fine for me. You have to be careful with the angles though!

Edited By Chris Denton on 08/11/2014 22:52:51

The cutting edge needs to be at centre height, and to get a good cutting edge, and clearance.  plenty of negative top rake.

Ian S C

Edited By Ian S C on 09/11/2014 07:41:17

Chris,

Sorry, perhaps I'm just being thick, but how does a 90 degree insert allow you to do chamfers without it first being rotated to 45 degrees?

I use triangular TCMT inserts and one of my turning tools has the insert set at a 15 degreee angle, so that the cutting edge is at 45 degreees to the axis of the lathe. In this arrangement, you use the edge of the tool (or part of it) as a "forming" cutter (even thought it is a straight edge) and when used in conjunction with a QCTP makes doing chamfers dead easy. Obviously, I have both left and right hand versions for chamfering both ways. You could use one of these tools mounted along the axis of the lathe for your internal chamfering if the job prevented "normal" mounting (at right angles to the lathe axis).

Regards Tom

90deg insert when placed in a holder at 45deg gives you 45deg on each side of the insert so you can do internal & external chamfers with the one tool when mounted along te lathes axis subject to clearance. This is much teh same as I use a HSS bit, the two holding positions of a Dickson type QCTP mean you don't have to move the toolpost

If you must have a carbide chamfering tool it is better to use a brazed tip rather than inserts. With a solid tool the underside can be washed away to allow chamfering of quite small dia holes. I had one when I was machining in anger on production work, after the initial grinding it very rarely had to be done up, and I was cutting very tough alloys used in jet engines.

This is what I currently use, for internal and external chamfers. It's coloured in red for clarity. 

Edited By Chris Denton on 10/11/2014 09:48:28

If the angle is decorative rather than critical, use a thread cutting tool in the same way as Chris' photo.

Neil

I found one of these in a set of brazed carbide tools today, some precision grinding under the tip and it's perfect!