Carbide threading inserts.

I want to make some M16x1.5 (ie metric fine) internal threads and have been looking for a suitable tool. I came across this **LINK**

Seems like a (suspiciously!) good deal - 16 quid for the tool and ten inserts.The inserts are designated 11IR A60. That meant nothing to me, but looking at the ISCAR website, I see "Internal 60° partial profile, laydown threading inserts. IR/L - Ground periphery and rake."

I guess they'll do what I want, but can anyone tell me what 'partial profile, laydown' means?

Robin.

Robin,

I recall that Andrew Johnston kindly gave an explanation of 'full profile' vs 'partial profile'

**LINK**

https://www.model-engineer.co.uk/forums/postings.asp?th=137131

Hope that's some help.

MichaelG.

Just be aware that tip quality can vary, last time I bought a "bargain" holder and 10 tips the tips were pants, ended up getting some decent tips that cost many times more but they made an unusable tool usable.

Very good point Jason!

I had some from Ebay a few weeks ago, total rubbish, clearly reject items!!

**LINK** are my choice for inserts usually.

Jim

I got a very nice internal threading holder and tips from JB at a show last year.

**LINK**

I use APT for inserts and holders not the cheapest but very good quality, deliver is quick.

I bought the self same set the other week and I am entirely satisfied with it.

JES

i am not going to recommend a tip or holder other than suggest the OP gives the low cost far eastern tooling a try. A few years ago the tips were hopeless, but now I find them entirely satisfactory as are the holders.

I am told by a production engineer that what lets them down are the manufacturing tolerances on both tip and holder, important for him when consistency is vital but of no consequence to us, mostly.

He also found that tip life was slightly reduced, something like 90% of what was expected of a high quality tip. Again, for us, of little consequence.

John

To get back to the original question...

As far as I can make out, the "laydown" bit simply refers to the tip lying flat like a ccmt tip rather than on one edge like a parting tip. Am I right?

Rod

Thanks for replies - the pics from Andrew Johnston in the thread MichaelG pointed to make the full/partial profile thing clear. I'll go for the KKmoon set bearing in mind the caveats about cheapo stuff - but JES found the inserts OK, so maybe it's a good deal. If so, ten three sided tips will see me out!

Still wondering about 'laydown' though - is Rod right, and if so (or not) what would the alternative(s) be for a threading tool?

Robin

The alternative is perhaps like these.

Rod

Lay down ones lay flat on the holder or sometimes a shim and the alternative are "On Edge" inserts

Thanks Jason, I didn't know about the 'on edge' system, all is now clear.

Robin

Has anyone found whitworth external form inserts on the Banggood site. I can only find metric. Lynne

From Koroloy out of Korea. Really good stuff also. These are not cheap, but do work very well. With care the inserts last a very long time. Have not found the full form inserts, but they do have partial form inserts in 60 deg and 55 deg, and there are the internal grooving inserts that can be made into the geometry you desire. The sizing is the minimum bore diameter . You can fit an 11 mm insert onto the 8mm holder. Just requires a shaped washer and a longer screw to do so. I have the 8mm carbide holder and the 14mm carbide holder, but have inserts from all 4 ranges. The holders are not cheap for the carbide, but is more rigid than the steel in the smaller 8mm one, which is about 5.8mm shank for the insert side. The 8mm is on a 12mm shank, the 14mm is on a 16mm shank. Both will fit on a Myford S7 Dixson holder. I did recut a holder to accept the 16mm shank, by cutting the upper portion of the block making the opening 16.1 mm from the 13mm that it was.

https://www.cutwel.co.uk/lathe-tools/multifunctional-lathe-tools/fine-tool-internal-grooving-system

Thanks for the tip on the 55 degree Whitworth form. I gave up looking on the assumption that carbide tips and Whitworth were not compatible!!!!!!!

Andrew,