Thread: TCT Inserts

Heeelllloooooo.... Studley....... what about TCT tipped saw blades for timber?????


That doesn't look like SO to me either John, I have nearly finished a White Cedar bowl & it looks very similar to that.

It's all speeds and feeds Cliff. The obvious thing is that each saw tooth spends only a percentage of it's time cutting. The rest of the time it is spinning in an unloaded condition back to have it's next turn.

A lathe tool doesn't get to share the job around like that. Importantly there are many grades of carbide that perform very differently. So no way to tell you for sure. One place I worked just used tips meant for low carbon steels. The silly thing is that they did all their work in Stainless, Brass and PVC. Got away with it too, although the tool life on Stainless wasn't that good. Mind you the tool life was much better when we ramped up the speeds a fair bit.

Juicy stuff this. You might have noticed I really like Carbide tools.

Studley

Mine came today. Son came into the bed room all excited. I think he thought the package might be for him.

Hi everyone,

I finally go a box (10) of the 17mm inserts, I've been waiting for some time. They end-up costing just under $10 each with freight to me.

I was disappointed that they didn't have the countersunk hole on them, as this normally allows a bigger (stronger) screw to hold the insert in place. This will be overcome quite easily, by changing my normal set-up.

So, as soon as I recover from my last go at drill and tap a 16mm HSS solid square bar, for the fitting of the 15mm insert, I will try to finish the tool once and for all. I've got plenty of timber waiting for the monster gouge...!

Cheers
RBTCO

Question: would a 12mm bar be too small to support that 17mm insert, considering that the centre is not weakened by countersinking and the sides take less stress than the front?

Originally Posted by Frank&Earnest

Question: would a 12mm bar be too small to support that 17mm insert, considering that the centre is not weakened by countersinking and the sides take less stress than the front?

Well, I can't think why not, even tough I would prefer to use 15mm bar. According to the steel supplier who supplied the 12mm stainless bars to you, they do not have 15mm but only 15,88mm or 16mm (imperial, metric). When asking for cost, I was given a quote of $23 + GST + freight for 1 (one), or $17x2 + GST + freight for 2 (two). Ouch...! Yeah, I had something in mind but, when I worked out about $55 to get 2 x 1' bars here, I gave it a miss! sorry.

I will put a couple in a envelope for you to try, no "problemo"!

Cheers
RBTCO

Thanks George, but that's not what I was thinking:

- I have three spare 12mm ss bars and plenty of ferrules
- NeilS has no bar and no enthusiasm for metalwork
- you have no bars but you have the skills and the tools to drill and tap them and make handles (no need to make them for double sided bars).
- we all have our inserts to try: 14mm for me, 15mm for Neil and 17mm for you.

What about I mail bars and ferrules to you, you make three tools, keep one for your trouble, and mail one back to me and one to Neil?

Neil of course will buy us a beer when we have the next shed meet . Is anybody willing to host one, anyway, or the last one at my place was so awesome that nobody feels up to following that act?

that was the one that I didn't get to Frank! I had a good record up until then.

Just a thought guys but you could buy a boring bar that comes with all the fiddly stuff done for the insert. Then you just have to put a handle on the end of it. Screws to hold the insert come included. Should be able to get something for $50 or less. Maritool(URL) have some and a good reputation. If you want to get the absolute exact thing you want Sandvik or Kennametal will sell it. Might cost more though.

Studley

Is there any reason why any or all of these insert shapes cannot be used on wood ?

http://www.pgstools.com/servlet/the-...bypicture/Page

s there any reason why any or all of these insert shapes cannot be used on wood ?

http://www.pgstools.com/servlet/the-...bypicture/Page

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They are designed for machining steel and will have a small radius on the cutting edge. With that they will not have the sharpness of tips ground specifically for timber.

But if buy a green grinding wheel that is designed to grind Tungsten tips then you can modify them to suit your self. Cost is pretty well the same as Ali Oxide white wheels, i f you do alot of grind ing you will notice the wear rate is much faster than ordinary wheels

I still reckon it would be interesting to try a regular tip on timber. You might find the tips intended for finishing on something abrasive like cast iron work.

The differences between the many tips is the profile on the top designed so the chip breaks. The radius on the edge is there to improve tool life. A really sharp edge on carbide tends to get rubbed off easily on steel or even aluminium.

Studley

These are the specs on one of the boring bars on Studley's Maritool site:

Shank diameter is .625 , Bar length is 7.5 inches
Minimum bore diameter of .72 inches
Bars have a flat on the top and bottom for easy alignment
Boring bar includes torx wrench and 2 insert screws (1 spare)
Uses series CCMT 32.5XXXX and CCMT 09T3XXXX insert
Also uses CCGT and CCET inserts, insert tolerance is the only difference
5 deg lead angle allows you to profile up to a 90 deg shoulder

So I'm right out of my depth here, but assuming that the Ci1 rougher handle is the best design here, the above does not have the slight backslope on the mounting section Cliff has mentioned.

Any other significant differences?

CCMT means
C = 80º square (oblong if you like)
C = 7º clearance angle on the front
M = tollerance class of the insert. I think at that size the tollerance is 0.05 mm on the inscribed circle, the thickness length of flank etc.
T = insert type. This one cuts on both sides of the face but not on the underside and has a countersunk screw.

Lots of info to get you going rssr.

It's called the sandvik coromant turning grades. I have a copy but at 500k for the PDF too big to post here.

Wouldn't you know it I can't find where I got it from Sandvik Coromant is a big company. Anyway if you want a copy say so and I will email it to you. It is two pages and explains what all the letters mean and so on.


Something I think you guys should consider is a tool like a TNMG. It is a triangle that has a neutral face. So it can be turned upside down to use the other side. So one insert has 6 sides to cut with. The thing with these though is they are designed to be used in a neutral holder which tips the cutting edge down a bit instead of being square.

Studley

I don't want to be a wet blanket, but after using one for a couple of weeks, and finding out for myself what a square insert can and cannot offer (not that I doubted , but we all have our quirks, don't we? ) I am not going to spend a lot more time experimenting with shapes and sizes.

I agree with : it is a sledgehammer, don't expect it to be wonderful at cracking nuts. It is not much worth using it on soft woods, the need to clean up the mess reduces the slight speed advantage. On very hard wood the time advantage is substantial and worth learning to master the butchering at a reasonable level. For proper turning, we all seem to agree that square inserts can not replace the traditional tools. I take it that round inserts work for hollowing: one thing I would like to experiment with is using a square one mounted at 45 degrees for hollowing cross grain. Should work like a spade drill, shouldn't it?