I am 7/8" spade drilling some A514 3" thick burned plate. I am doing this in a 15 hp cnc mill.
I spot the part first, and then drill.
I have a part, that has an unusually hard spot at the bottom of the hole.
It has eaten 3 super cobalt tips already, just in making 2 holes! I have to finish this part, and have another 8 behind it. This is a repeat job. This is the first time in maybe 50 parts that I have run into this.
My thinking was to order 1, or 2 carbide inserts fro this part. Then go back to super cobalt Tin coated (unless you all think I should do otherwise)
What grade carbide should I order? C2, C3, or C5?
Thanks,
Doug.
I spot the part first, and then drill.
I have a part, that has an unusually hard spot at the bottom of the hole.
It has eaten 3 super cobalt tips already, just in making 2 holes! I have to finish this part, and have another 8 behind it. This is a repeat job. This is the first time in maybe 50 parts that I have run into this.
My thinking was to order 1, or 2 carbide inserts fro this part. Then go back to super cobalt Tin coated (unless you all think I should do otherwise)
What grade carbide should I order? C2, C3, or C5?
Thanks,
Doug.