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Need some help

Stang393

Plastic
Joined
Feb 10, 2020
I am a total newbie at this. I bough this kit off amazon for my lathe. I know its not the best but to start off with it was good enough. My problem is I want to buy some different carbide for the tools. I did a google search and found a how to read a carbide web page but it didn't fully answer my question. My set came with CCMT21.5.
C= diamond
C= 7 degree
M= .002-.005
T= 40-60° double countersink

My question is what is the 21.5 my guess is
2= is the size, which cart say 2=.25 what does this mean?
1= thickness so i have a 1 inch thick cutter?
.5= radius not sure cutting edge?

I still don't know the size of the whole that my screw goes though to screw down the carbide to my holder. Also when looked for new carbide what numbers do I need to transfer because of the size holder I have. I know the shank is 1/2 X 1/2 but that it. Thanks for the help and if this is not clear let me know an I will try to clear it up.
 
I am a total newbie at this. I bough this kit off amazon for my lathe. I know its not the best but to start off with it was good enough. My problem is I want to buy some different carbide for the tools. I did a google search and found a how to read a carbide web page but it didn't fully answer my question. My set came with CCMT21.5.
C= diamond
C= 7 degree
M= .002-.005
T= 40-60° double countersink

My question is what is the 21.5 my guess is
2= is the size, which cart say 2=.25 what does this mean?
1= thickness so i have a 1 inch thick cutter?
.5= radius not sure cutting edge?

I still don't know the size of the whole that my screw goes though to screw down the carbide to my holder. Also when looked for new carbide what numbers do I need to transfer because of the size holder I have. I know the shank is 1/2 X 1/2 but that it. Thanks for the help and if this is not clear let me know an I will try to clear it up.

Pix of lathe would help...and Oh yeah, "in before the lock"...:ack2:
 
I can get a picture of the lathe not sure how that going to help when I’m looking for carbide insert help.
 
Iv already did a goole search if you would have read the post. It did not answer my question.
 
Insert Designation Chart - provides ANSI and ISO designation code definitions for carbide insert shapes, relief angles, tolerances, chipbreaker codes, hole types, size values, thickness values, radius values, wiper lead angle, wiper clearance angle,

Here's a useful chart with explanations of those numbers at the end, which encode dimensions. Keep in mind that there are both ANSI and ISO numbering systems that can be used mostly interchangeably to describe insert dimensions. CCMT21.5 is in the ANSI system (decimal point is a clue).

You're getting flak on this thread because you didn't write a title for it that explained your question. So it will probably be closed but at least this will get you going. Follow the rules stickied at the top of the forum ("Machinery Discussion Guidelines", "Topic titles need to inform what your topic is actually about", "Off Topic Post Guidelines") and this place will be a great resource for you.

Oh, and ignore grumpy old digger doug, he's just assuming you have a "forbidden" hobby lathe that isn't allowed to be discussed here. He's probably trying to bait you into posting it so the thread gets closed sooner.
 
If your new to this you shouldn’t even be thinking about carbide tooling. Your don’t have the experience and your lathe doesn’t have the power or rigidly to handle carbide. Get some HSS tools from the flea market and practice grinding them till they work properly.
 
Not knowing the lathe you have I'd still have to agree with getting HSS first. Being new to lathe use will mean you'll likely break a lot of carbide and that gets expensive. A HSS bit will not break/chip/shatter like carbide will and can produce a good finish. When it gets dull it's easy to resharpen, carbide inserts are mostly throw away when they get dull. The cutting geometry for HSS can be changed to suit your purpose, carbide inserts cannot. As posted above, your lathe may not even be fast enough or rigid enough to use carbide. Carbide is NOT always the right choice either. Carbide is often best for long production runs or difficult material IF you know the rules for using it. I often prefer HSS over carbide so I can set the cutting geometry and have a freshly sharpened edge.
 
Even if you can't figure out what the designation on the inserts means, well, why not just buy some more CCMT21.5 inserts?
 
Thanks your for the responds

My question is what is the 21.5 at the end be of the CCMT? from looking at the cart I am assuming this is what it means?

2=.25 I'm assuming that mean the carbide .25 big
1= thickness so i have a 1 inch thick cutter
.5= radius cutting edge
 
The chart, cited above, tells you exactly what your insert is. Study that chart.

If you take the time to do a search on amazon for ccmt21.5, you get an ad for inserts that includes:

CCMT21.51(CCMT060204)


I think that the 06 means 6mm cutting edges. Which is clearly shown in the online chart to be equivalent to the "2". Is the 6mm this about right? The whole insert is about 1/2 inch long?

51pPOK2g8EL._SL1000_.jpg
 








 
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