[cob]

hello everyone,
trying to see if someone can help me , I am trying to machine a 5 inch SST that is to be finish at .050" THICK, I started with a .072 thick,
I would like to machine it with in .001 flatness can someone give some ideas. on how to hold the part speed and feeds and what type of inserts,
thank you

[metalmayhem]

1st thought would be vacuum except I'd expect possible bowing on that thin of material . I've never tried it but this looks interesting https://www.miteebite.com/wp-content...EN-II-7-22.pdf
They always have nice products and it should have enough hold for light cutting . With it being a wax it's a bit questionable what kind of parallelism can be expected .

for a one off I'd probably go with a few dabs of crazy glue and test it's strength , but then I like to dabble with the dangerous side of life

[ToolHIT]

That is a tough application! To hold the part I would use 3M Double Sided Tape:
https://www.3m.com/3M/en_US/p/c/tape...ding-assembly/

You definitely need a free cutting face mill to keep tool pressure down and keep the material from folding up (hopefully it is 304 or 316 and not 303). The ideal cutter would be a 45 degree cutter with positive inserts that is 2" diameter or smaller. The 45 degree cutter will lead in to the cut and the positive inserts will also keep tool pressure. If you have one on hand then I would run it with just 1 insert so it cuts like a fly cutter and you have less cutter contact on the workpiece to keep it flat.

If you don't have one on hand then here is the 45 degree 2" Diameter positive cutter we would recommend in a Kit (this will be the freest cutting geometry and we would run 1 flute):
https://www.toolhit.com/products/kit-f45-sekt-d200z5

Run it at:
SFM: 200
CLPT: .002"-.003"

Hopefully this helps!

Mike

[metalmayhem]

a possible problem with double sided tape is that it's going to take initial pressure on the part to make it stick , if the part bows at all while getting it to stick then the flatness will be lost .

With little holding power it's likely safer to use an end mill vs an insert cutter due to the amount of force from an insert mill . A fly cutter with a sharp hss bit may be a better alternative . It would be an intermittent cut so it's hard to say how that would react as well .

if it's true stainless it won't be magnetic but if it isn't then the best thing would be a magnetic table