Machining Cold Rolled Steel, Precision Headaches Guaranteed! 

Be sure to check out my next video on milling dry vs with coolant here: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-06_10JTpAgg.htmlsi=EBd-QTO0RZoKHLc1

Have machined parts like this in the past, always used flat ground 1018 stock. Was a bit more money but saved time in the end. Had to machine base plates for a machine ( 38 x 42 x 3/4 thick ). Started out with thicker stock then had them Blanchard ground flat and parallel , this material was A36 hot rolled steel.

Having seen CRS go "La-Twang!" more times than I can count during 40 years as a machinist, I try to use it as little as possible

We make some clevises out of 2” square 1018 CF. Mill a .812 slot 3 or 4” long. Have to squeeze them back parallel when we are done with them. Can go out as much as .03”.

This is interesting to me, I have a different theory that the cutting process on the open end of the vice is letting the metal move out from the pressure, and heat combined with the induced inherent vibration of the cutter head. Vibration can stress-relieve metal at certain frequencies. Is it possible to hold the cut end in the vice and still cut the slot that would be an interesting test? I'm not a machinist but worked on rolling mills for 47 years. The Cold Rolling process induces stress lines in the opposite direction of the rolling direction or vice versa can't remember exactly and the annealing process may not remove all of them to maintain strength.

You really should be running your test indicator with the tip closer to parallel with the measured surface in order to reduce cosine error. The direction of indicator travel should be inline with the error being measured. I've had the similar distortion issues when cutting Brass and nylons as well.

very informative, thank you for sharing this information,,,,,best wishes from Central Florida, Paul

Very informative. Thank you.

Some plastics are even more of a problem. Cut it to a half of milimeter less and you haw to leave it for a couple of days. It creeps under its redisual tension, but annoyingly slow

👍👍👍👌

Why not simply vacuum or hydrogen furnace anneal the cold rolled material? Similar to normalizing castings, but no surface oxides. Maybe one could even order it treated that way?

Try liquid coolant.