Jump to content
I Forge Iron

Cobble in Rolling Mill

Recommended Posts

I work maintenance in a roll mill and this is a common occurance, maybe an average of 3 or 4 times in a 12 hour shift, depending mostly on what size is running. The smaller the product the harder it is to get it to the end, the difference between pushing a rope or a spaghetti noodle. Every set of rolls it goes through reduces it's diameter by maybe 10 to 20 percent, but that material has to go somewhere, so it grows in length. Which means it also picks up speed by that same 10 to 20 percent every millstand it goes through, in our mill there's 18 millstands. The 5-1/2" billet enters #1 at about 2 mph and exits #18 as a 180' long railroad spike 1600 degrees travelling about 40+ mph. So as you can imagine that it doesn't take a much of problem to cause a cobble. I would guess that an average cobble takes about 30 min to clean up and get back to running, not a very fun part of the process.

Link to comment
Share on other sites

Sounded like a laugh as it started.

I heard about those at the mills in Cleveland and Elyria. They ran oxygen only torches since a preheat fuel was not needed, and it was 1/2 the weight to carry around. This is from a friend who worked at a couple mills in Cleveland and Elyria Ohio.


Link to comment
Share on other sites

Youch, a contractor just died yesterday working for AK Steel Holding at an American coking plant. A lot of people have died over the years pulling rocks out of the ground and the danger seldom stops there. Glad no one was hurt, made for a pretty funny watch.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Create New...