What kind of coating or surface treatment is used on milling and turning insert holders? Seems invincible to corrosion. I want to make my own from 4140. Suggestions?
What kind of coating or surface treatment is used on milling and turning insert holders? Seems invincible to corrosion. I want to make my own from 4140. Suggestions?
One that I have looks to be hard chromed, the others look like a black oxide finish. Gun bluing maybe?
https://www.youtube.com/watch?v=f4qeen12fuc
Jim Dawson
Sandy, Oregon, USA
The appearance is right for gun bluing Jim Dawson, but I've done my own cold bluing at home, and didn't find it very durable. Maybe it would be OK as long as it was only used in conjunction with well-maintained coolant.
Whatever it is that they do to commercial tooling seems to stand up to coolant even if it's mixed too thin. I've seen machines that get a bit of surface rust on the turret, table, or way covers, but the tooling never gets any rust. I've always wondered if it's more the coating, or the alloy it's made of. I'd love to get some insight from anybody who knows!
Does it depend on what type of tooling ,does most have chromium in it but I believe it's just the blacking stuff ? cast iron will surface rust in moisture prone areas quickly .
diamond core bits are the way to go, with quite high rpms
and with water or water/detergent coolant
If you had placed it on the hot coals, open, the heat should have driven the water off as you intended, drying before it rusted.
With the lid on, the moisture was trapped inside, and had opportunity to cover every inch of the metal - and, heat speeds up the reaction, and you have a layer of rust.