Don't belong to hardly any online forums so I'd figured I would ask here in hopes of someone pointing me in the right direction. The company I work for has a die that is made out of stainless that had a nut get pushed through and damaged it. In the past when these were damaged everyone including the manufacturer said it couldn't be fixed due to warping the thin metal when heat is applied. A new die is in the neighborhood of $20k.
This is the first time this happened where I saw it in person so instead of taking everyone's word for it, I wanted to reach out if anyone has any experience in fixing something like this or can point me in the right direction. Seems to me a competent body shop that does restoration work would be a good place to start, but I know stainless is a different animal and really might not be fixable.
I would provide a picture but not able to currently locate it. The basic shape of what I am talking about is a curve with a radius of around 3-4 inches with slots that are about 2.3 mm wide and 150 mm long. The slot is bent and that is what needs to be brought back to a circular shape either through bending and shaping or cutting out the bad piece and welding in a new one.
Straightening Stainless Steel
- Thread starter SVTCobra
- Start date
- Status
I'm sure some here can help, but the Practical Machinist forum is full of guys who spend their days thinking about how to work with metal.. so that's another resource for you.
http://www.practicalmachinist.com/vb/
I don't know which alloy you are using, but I have always found stainless steel difficult to work with due to the fact it work hardens.
Bend it once, that's OK, go to adjust the bend and the now work hardened part stays fixed in place while the material around it moves instead. Same with cutting in a band saw, cuts OK, pause for half a second and it becomes hard on the face and difficult to cut. Push through the hard bit and it suddenly takes off again.
No cutting and welding, find a good (real good not a bondo hack) that can hammer and dolly it, shrink it then pick and file.
I know a few old timers that can do it around here but in MI There should be a lot of guys able to do that work, time to make some calls.
Try "Unique Machine & Tool" in Mc Kees Rocks PA 15136 Phone number 412 331 2717 ask for Martin Rubeo he is the owner and a top notch metal machining and welding man.
Thanks to everyone for their replies. I will look into it. Just to clarify this is either a 314 or 304 stainless used for food production. It's located in Kentucky. The local machine shop hasn't been able to fix this in the past, so worth a shot to send it to a body man or another machine shop instead of buying a new one.
Based on description I am reading I have seen others weld into the damaged zone where the nut pushed through then machine excess away. Kind of like filling a tooth cavity but it's metal then remove the excess. I am not a machinist or die maker though just what I have seen.
Kestas
Staff member
That sounds like a good way to repair it. I'm away from my books, so I can't recommend a filler metal. A good welder should know. Maybe pure nickel?
Does the die see appreciable stress, or does it just take up space?
It mainly takes up space. It's a solid chunk of stainless that is thick where it's bolted to the rest of the machine and where the food is pushed through the die is where it's thin and has the damaged slot.
Originally Posted By: Kestas
That sounds like a good way to repair it. I'm away from my books, so I can't recommend a filler metal. A good welder should know. Maybe pure nickel?
Does the die see appreciable stress, or does it just take up space?
BTW some stainless has nickle, and some does not. To find out see if the stainless will stick to a magnet. If it sticks to a magnet it does not have nickle. If it does not stick to a magnet it has nickle and should not be used in anything that comes in contact with food.
Originally Posted By: tig1
408 stainless will take to a magnet because of carbon and it does have some nickel. All of the food grade stainless that I have welded for companies, required 316L tig rod.
- Status
