best way to file a thin steel strip

[green]

I need to insert a 1/8 x .5"x 40" steel strip inside an 8020 piece. The strip is a bit too wide by .025. I could place in a vise and file it, but given the length and my desire to have a straight edge, I am not sure it's wise. I have a mini mill, but how would I mill it continuously?
thanks
tony

 

[Ulma Doctor]

you can mill or file with this method,
sandwich the piece to be filed/milled between known square metal backing of the correct height you wish to end up with.
put the set up in a vise and file/mill down to the backing.

or scribe a line on the work and sandwich between backing for visual reference( if you don't have backing of the correct dimension) and file /mill to the backing.

 

[ProMetalShop]

When I have long pieces to cut or punch holes in, I set up guides on each side and pull it threw. With that thought maybe a tight set of guides on the side, and one on the top to hold the work piece down in place. When you have milled to your mills length, loosen the hold down clamp and slide the work piece down, and re-clamp. I can post a picture tomorrow when I get to the shop of an example if needed.

 

[JimDawson]

What you need is a vertical vice about as long as your mill table.

Bolt/clamp a piece of metal to the table as a backstop, maybe a nice straight piece of 1/4 x 2 aluminum.

Clamp the steel strip down in several places with a piece of square stock(key stock) over the top (the top ''jaw'' of the vice)

Mill, move, rinse/repeat, until you have the whole length milled to size.

You might want to put the whole setup on a backer board or other sacrificial piece so the tool can't hit the table

 

[Dave Smith]

Tony---there are many ways of doing it but if you are real steady with your hands I would clamp it between two straight pieces of metal so just the excess is sticking out--then use your angle grinder with a flap disc on it and remove the excess easily--flap discs remove metal fast and smooth--the more you use them the better you get---this would be my way--------Dave