Question for a machinist

[modelman]

What is a chip breaker? Can you buy them or do you make them? Can someone post a picture of one please?

[9W Monighan]

It's just a convex area behind the cutting edge usually seen on insert tooling. What it does is curl the hot chip in a tight radius making it break in small pieces.

[pugs]

Yep, some older carbide insert tooling I've seen had separate chip breaker that you could slide upto and away from the edge depending on how big of chip you were making. most modern, average sized carbides are molded into the insert. Many mfgs have several different styles for different inserts, different applications such as roughing or finishing.

The little islands in this are the chip breakers, the dots are more for holding flat in the tool.
http://4.bp.blogspot.com/_KC8wrXv33lY/TCi6GDpJTCI/AAAAAAAAAFo/osAbXj4NXsk/s1600/chip+breaker.jpg

[modelman]

I am turning my wheels from 2" T-6 alum.. I have to take them down to 1.700". When roughing them in I am taking big cuts at a fast feed rate and the "worms" I call them coming off the cutter are long stiff and sharp. I have already taken a couple to the face. I have to stand there and fight them off and I was just wondering what would stop this.

[pugs]

Aluminum is a string mess usually, using a HSS bit I assume?? You could try and rig up a chip breaker top piece kinda like old wood planes have. it might help but HSS and aluminum mostly spells stringy mess. Make your self a chipgaurd is the easiest solution.
http://media4.rscomponents.cataloguesolutions.com/MediumProductImages/R774391-01.jpg
Have seen some like this, have seen others made from a magbase with locline (hose and a piece of lexan) others that just had apiece of lexan bolted to the back of the tool post or compound table.

[pugs]

Oh and in the description of aluminum. T-6 (typically T6-511) is the temper. 6061 or 7075 is the alloy number, both of those alloys can be had in T-6, yet are 2 different material both in strength and composition as well as price.