Insert tip query

Hi,

Probably an often sought answer but i would like to know if anyone recognises this tip because i'm not good with the cryptic naming of tips.

It's for a 3/8" shank right hand turner, it's brilliant but the tip is getting a bit knackered and it's 1/4" parallelogram and the counter bore on the torx screw is something like 8.5mm. It's silvery grey coated.

Michael W

Hi Michael, looks like a CCMT , of a size CCMT 0602?? on a SCLC-R

Michael something amiss here, If the insert is approx ¼ " then that would be a CCMT0602??, but not with a hole of 8.50 Ø !!!

8.5mm long?

Martin

Ah thanks, yeah i think i got it wrong,  :P brain not in gear. i'll go for the CCMT 80 degree rhombus type from ARC?

but i do know it's 6.35 across

Edited By Michael Walters on 04/05/2016 14:25:06

Thats more like the sizes, Most certainly its a CCMT 0602??. [ the 2 questionmarks are only because I don't know the nose radius ] You will have a choice of 02 04 or 08. [at least in production makes] im not sure about ARC ones.

Cheers.

Thanks Ray,

I looked up 0602 on cromwell and sure enough i think i've found the culprit the sizes are a close match.

I'm pretty sure i can't measure that radius without a shadow graph so i'll settle for straight down the middle with a rad of .04

**LINK**

I'm actually almost tempted to engrave the name of the tip on the side of the shank of  the tool 

Michael W 

Edited By Michael Walters on 04/05/2016 16:28:50

Hi Michael, The nose radius has no effect on the tip size, an 02, 04 or an 08 will all fit in your holder. It's letters and the first 2 sets of numbers that denote the insert style / size. CC**'s are very versatile, they let you turn and face with the same tip without having to alter the toolpost. So you will be "good to go" with your CCMT 0602 and whatever nose radii you want out of the 3 standard radii.

Cheers.

And Hagrid-sized fingers!

I was just showing harry how you could use the philosophers stone to cut materials impervious to magic, he didn't believe me when i told him it was tungsten carbide.

Michael W

Bit of a late addition but i have received the new tips and it sits on there ok, it began to ride up a little as i screwed it in place but a bit more force pushed it down again, different colour to what i was expecting;

As a small aside, I keep losing particular tools now and again so i've decided to paint them with small blobs of red so i can easily find them, might be a good tip.

I paint Tommy bars and collet spanners red so they stand out, also paint brushes used for sweeping swarf out of my mill vice and off the lathe. I'm a big fan of Bondhus T handle hex keys which by happy coincidence have bright red handles.

Some years ago I bought T-Handled Allen wrenches in Imperial and Metric. The handle on the Imperial set was blue; that on the Metric set, orange.

So I decided to paint blue bands on my Imperial open-ended and ring-spanners; orange on the Metric. A few other blue/orange Imperial/Metric markings followed thereby establishing "The System"

Then I bought Imperial and Metric sets of ball-ended Allen screwdrivers. The Imperial had orange handles; the Metric were blue.

Hi Michael, Glad you got your replacement inserts ok. If you go to the thread entitled "Jason's tips " you will see I have put up a few pics of inserts with various coatings. Also when mounting a new tip, always make sure that the insert seat is perfectly clean and the threaded hole also. I don't know the make of toolholder you show in the pic but you will often find that the "budget " makes have the sides of the insert seat at 90° when the insert has sides of 7 ° not 90 °, and as such does not make full contact with the sides of the insert. Consequently that can chip the top edge of the insert when clamping down, just something to watch out for.

Cheers.

Edited By JasonB on 07/05/2016 07:46:12

Raymond, not all well known maker inserts have in-built rake of 7deg, various angles are used depending on use, also some are just 90 degrees.(zero rake)

Emgee

Emgee, Im fully aware that not all inserts have 7° rake. The insert in this thread is a CCMT its the second letter thats important here "C", if the insert was anything other than 7° then it ceases to be a CC ** and uses a dedicated holder. EVERY CC** is 7° Yes,, there are other clearance angles but they aint CC. SCLC holders for CC at 7 ° . Yes, other clearance angles MIGHT fit, but that does not make it correct.

Raymond.

Thanks for the comments, I'll take a look at those pics ray.

I'm not sure why it jerked slightly but perhaps a little piece of dirt got wedged. It's a good point to consider if the slot has been machined with the appropriate angles.

it's a sherline tool holder so they made it. It's not clear on the photos but theyve even machined a pocket in the corner of the tool holder to make sure the edge of the tip or any dirt sitting inside it has somewhere to go, i trust they've designed it to the N'th degree as even though the holder is powder coated, you can see the machining marks on it, probably on a cnc.

It cost a pretty penny, it came in a set of the left and right hand cutter 80 degrees, 3/8 shank at about £50-60?

I think its worth the money as i've bought whole sets of bigger tools that have made terrible cuts in the materials. These ones i've used for ages and it treats steel and aluminium a little kinder than most. 

When i started machining, an old boss of mine recommended i use 3/8" cutters like the ones he used on his chip master, he didn't really rate my idea that a bigger shank meant tons more rigidity and therefore a better tool, through experience i've realised he was probably right, doesn't matter that much. 

Michael W

Edited By Michael Walters on 07/05/2016 15:02:33

Michael, to answer your original question you may find the following explanation of the lettering for inserts helps.

First letter denotes insert shape, C=80deg Rhombic, D&K=55deg, R=Round, S=Square, T= Triangular, V=35deg.

Second letter denotes clearance angle. B=5deg, C=7deg, E=20deg, N=0deg, P=11deg.

Third letter denotes tolerances on thicknes and inscribed circle size, M denotes +or- 0,13mm for thickness.

Fourth letter denotes type, A,N,Q & W are flat top, G,M & T tops are shaped to provide cutting clearance and chip breaker.

First 2 numbers denote cutting edge length, 06=6mm on C shape insert, 07=7mm on D shape insert.

Next 2 numbers are insert thickness, 02=2.38mm, 03=3.18mm, T3=3.97mm, 04=4.76mm

Next 2 numbers are for nose radius, 02=0,20mm, 04=0,40mm, 08=0,80mm, 12=1.20mm.

The ISO codes sometimes have additional info such as PF for finishing or PR for roughing.

Hope this helps, Emgee

Emgee, As I had already answered Michaels original question re his insert. I mentioned the fact that many [but certainly not all ] far eastern toolholders that masquerade as SCLC ones do not in fact have the sides of the insert pocket machined at 97° to accommodate CC** inserts. You go on to mention various clearance angles, one you mention 11 ° makes that insert a CP** ,, outwordly they look very much like the standard CC** but [and here's the but ] they use a toolholder iso SCLP, [and a few others ] and that holder[s] has the sides machined at 101 ° That is the reason I pointed this out to Michael. When the insert sides are machined at 90 ° for positive rake inserts then thats when the insert can suffer damage to one or both cutting edges that contact the sides. The toolholder must be machined to match the insert side clearance angle. It was the fact that Michael had some difficulty in seating the insert that prompted me to mention that [often ] overlooked fact.

The up shot is ,if ANY toolholder that is supposed to be designed for ANY positive rake inserts has the sides simply machined at 90 ° then it's not to any recognized standard.

I would expect Michaels Sherline toolholder would adhere to the standard, and therefore be "properly " designed.

Edited By Raymond Anderson on 08/05/2016 08:28:05

It's a good point about the socket machining. I haven't checked my insert holders to see what angle they have been machined at but I suspect they are 90°. I haven't experienced any side chipping but as Its only the tip that does 99% of the work in my shed its not likely to be a problem anyway.