I'm gathering materials for a rolling mill build and am planning on using some of the hydraulic shafting I use for hammers and top tools as the rollers.  I need to get the chrome off, but how?  When forging hammers and such I simply leave it on and it comes off with the scale while working it.  The only thought I have for this application is to spin the shaft and use a hand grinder to grind it off then turn it down to a uniform thickness on the lathe.  I'm using titanium nitrite lathe bits, I'm assuming the chrome plating would not redly turn off.  Also, any idea how thick it is?  I'm thinking grind, check with ferric chloride, keep grinding till there is no sign of it then turn to diameter.

Thanks

Impressive, you have been burning Chrome plating in your forge and your still alive to tell us about it.. Wow...

there are many more I suggest you read them

I thought the dangers of hexavalent chrome was mentioned in plenty of places here that we knew better than burning off the chrome. 

Steve is correct those are good references.

We recently discussed this topic in great detail.

Check out "removing chrome from copper" for more detail.

https://www.iforgeiron.com/topic/53234-removing-chrome-plate-from-copper/?tab=comments#comment-569585

I hesitated repeating all the salient details in that thread. It would have been a real labor intensive job.

Hexavalent chrome is a killer.

Regards to all the 'gangue'.

SLAG.

 

Good references and I have been reading up on them.

I am actually more concerned with grinding the chrome off than with burning it off.  My gas forge is outside and well ventilated and I'm not dumb enough to be downwind of it.  And before you start harping on poisoning my neighbors, the closest neighbors are a half mile away.  The immediate grinding dust can be taken care of with a respirator, but the particulates that would remain everywhere is an issue I don't want in my shop.  Frankly from what I've been reading, I'll likely be looking for another source for the rollers as I don't want to grind the stuff in my shop.

FYI, hexavalent chrome vapors are produced when welding stainless steel, and is found in some public water systems and drinking water.  It's nasty stuff for sure, but if precautions are taken it's a manageable risk.

If you have a stout lathe make a heavy cut  that goes *under* the chrome layer and not deal with dust or fumes...If you have a light duty lathe I would not suggest any method due to liability issues.

(I bought my first house from the widow of a fellow who did something stupid working on it and electrocuted himself; left two small kids too.  Rather a wake up call to me and my rather cavalier ways in the shop...)

Thanks, that's a method I may explore, not sure if my lathe is heavy duty enough, but the worst that will happen is a broken bit or slip the belt, not sure if I can make a heavy enough cut or not.  More than likely I'll wind up just getting a couple feet of mild steel round stock and dressing it up.

I've worked too long in the oil field and military before that to have very much of a cavalier attitude when it comes to safety.

When I worked in the patch the figures were that about 1 in 5 "career workers" had a major injury during their time.  A friend of mine was an EMT in the patch and you didn't want to get him going about the stuff he had to deal with---though they finally got the law changed that they could presume death under certain circumstances---prior they were supposed to do CPR even if it was a walk between head and chest to do it...

If they are hard chromed, leave it on. We had swaging dies at one place I worked at, and they were hard chromed for better wear resistance. Chrome is extremely hard and slippery. The chrome will also keep them from rusting and remove the need to keep them constantly polished. 

As for removal, do you have a local chrome shop? If so they can reverse the process and remove the chrome. 

 

May be too slippery for the rolling mill to work!  They need some grip to push the metal on through.

14 minutes ago, ThomasPowers said:

May be too slippery for the rolling mill to work!  They need some grip to push the metal on through.

the McDonald mill does not push metal through. the operator pulls it through the roller dies

The dies produce the motive force. A human can't provide the squash necessary. A friend of mine has one and that's the way it works. You place the stock between the dies and then tighten them and they push the stock towards you.  Your pull is trivial. In fact if you drop the tongs it will still push the metal towards you.

I've been in the oil patch for about 17 years now and only witnessed a handful of incidents.  They have really tightened down on safety, to the point at times it seems like you can't get anything done.  Then again, at one point they were crippling and killing people left and right, so something had to be done.  One rig I was on went two years without a LTI.  Of course, this is mostly been ultra deep water, back in the jack up days we got away with more stupid stuff.

I haven't used a rolling mill yet, but I seriously doubt there is any way you can "pull" a billet through the rollers if you have any reduction going on at all.  In the plans they do state that you can occasionally "help" pull the billet through, but it seems it's more about getting the rollers to bite and do the pulling than you physically pulling the billet through.  Hughe does state that you have to brush flux off damascus billets before rolling as it will act as a lubricant.  That tells me the rollers can't be too slick or they won't work.  That's one reason I don't want to leave the chrome on, another is that I figured it would burn off while rolling, if it would even roll as slick as it is.  I'll know more when I get it built, till then it's educated guess work.

i dont disagree with that, I was  pointing out the pull not push action for operation,   but I get it

I got you, no worries.  The pull through action is one of the things I like about the design.

pull and push are the same thing with just a sign change....