Tcmt 32.51 Vs 32.52

JeepsAndGuns

JeepsAndGuns

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Can anyone enlighten me as to the difference between the two?
Going by the breakdown of all the letters and numbers on this site: http://www.carbidedepot.com/formulas-insert-d.htm It says its the radius. So what exactly is that when it comes to carbide inserts? Is it the tip? Is one more pointed than the other?

Basicly I have some import toolholders that uses the triangle inserts. From what I have been able to find, these should be TCMT 32.51. But I was wondering what is different about TCMT 32.52.
Thanks.
 
Just the radius. Small light machines don't always do well with a larger radius, but you can get a better finish if the machine is capable. Keep in mind that if you switch in the middle of a feature you are cutting, your zero setting will change.

The 2 is a larger radius.
 
From what I've seen the last number is the radius as Tony said measured in 64ths of an inch.
Dave
 
Let me make sure I am understanding it right. When you say radius, basically it means how pointed the tips are?
 
JeepsAndGuns said:
Let me make sure I am understanding it right. When you say radius, basically it means how pointed the tips are?
Click to expand...

Yes the tip radius. 1=1/64th" radius of the tip. 2=2/64th" or 1/32" and so on.
 
This is why there is a G-Code for tool nose radius on a lathe, if the Tool Nose Radius is off any taper will be off diameter.
 
As will edge breaks, bevels, and radii in and on corners.
 
I had to use what I call a WCET (Will Chatter Every Time) insert today, TPG 324 which has a 4/16 nose radius, I turned the part .060 short in Z and faced that amount off with the big radius tool afterwards.
Did most of the turning with a 1/16 nose rad. tool, the big Radius will ruin your day but that is what the customer wanted.
It did chatter like mad at the full depth of cut, the part is 73" long by 5" 1045 steel bar with 6 different diameters, each diameter had a fillet radius callout at the inside corners.

The 1/16 radius is on the right of the picture of course.

My advice would be DO NOT BUY any large nose radius inserts for use on a hobby type machine regardless of how inexpensive they might be.
Good Luck

29m2l20.jpg
 
A large radius on a finishing cut can produce chatter on a light duty machine. When we transition to a large radius from a small radius we change axial deflection, which is minimal, to radial deflection which can excite the natural frequency of the part to produce vibration/chatter. One way that I have eliminated chatter on my machine is spin the part and shut off the motor and as it is coasting to a stop, I will hand feed to the finished radius diameter. I will do this only in the corner rad. Otherwise I am finishing with a small radius and leaving a little material in the corner for this method. This may take several starts and stops, but it works for me. Try to withdraw prior to dead stop. Try it a few times and you will soon be able to anticipate when the spindle will stop. This method works great for grooving as well. If you have a choice, use an insert grade with a high "P" number (indicates steel grade) in the ANSI/ISO system. For example Widia WP30CT, Kennametal KCP40, Sandvik 4335, Mitsubishi 735.
Numbers run from 1 to 50, 1 being high and wear resistance, and 50 indicating high toughness (won't break when you stop the spindle or with impact).

Good Luck!
Gary
 
I believe a TPG 324 has a 4/64" radius, not 4/16". No matter, its a big radius and should be reserved for rigid machines, or someone with the patience to play around with a variety of speeds and feeds to find the sweet spot for the particular task.

michael
 
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