## Plate Rolling Formula

## Plate Rolling Formula

(OP)

I ran across this formula, but it is only good up to 180Degrees?

(.01743xrad)x degree of circle

And I beleive this is not true as well: given

Roll-out flat pattern:

OD = 6.375 material .375 steel

Cir. 6.375 x 3.1415 = 20.027

Formula: (.01745xR) (180 Degrees)x2 =

(.01745x3.1875) x (180)x2 =

(.055621875) x 180 x2 =

10.11937 x2 =

20.023875, which is the same as cir.??

A better formula appears to be: but for alum. only??

(I dont know where the .0078 factor cam from)

(.01745xR)-(.0078xT)x(180 Degrees)x2=

(.055621875)-(.002925)x180x2 =

(.052696875)x180x2 =

9.4854375x2 =

18.970875

But evern better "I hope" is AutoCad's factor formula:

(for mild steel: A36)

By AutoCAD: using .407 factor Times thickness

= .0763 of the 3/8

Then offset from the insideat this factor,

you get: Length was a total of 19.329"

This seems closer to a real stretch-out pattern!

Can anyone confirm??

(.01743xrad)x degree of circle

And I beleive this is not true as well: given

Roll-out flat pattern:

OD = 6.375 material .375 steel

Cir. 6.375 x 3.1415 = 20.027

Formula: (.01745xR) (180 Degrees)x2 =

(.01745x3.1875) x (180)x2 =

(.055621875) x 180 x2 =

10.11937 x2 =

20.023875, which is the same as cir.??

A better formula appears to be: but for alum. only??

(I dont know where the .0078 factor cam from)

(.01745xR)-(.0078xT)x(180 Degrees)x2=

(.055621875)-(.002925)x180x2 =

(.052696875)x180x2 =

9.4854375x2 =

18.970875

But evern better "I hope" is AutoCad's factor formula:

(for mild steel: A36)

By AutoCAD: using .407 factor Times thickness

= .0763 of the 3/8

Then offset from the insideat this factor,

you get: Length was a total of 19.329"

This seems closer to a real stretch-out pattern!

Can anyone confirm??

## RE: Plate Rolling Formula

## RE: Plate Rolling Formula

For a large radius this point, sometimes called the K factor is closer to the middle of the metal thickness. not the inside edge.

Here is a link to a bend program that can be downloaded

http://www.ciri.org.nz/bendworks/bending.pdf

B.E.

## RE: Plate Rolling Formula

This the neutral axis of bending the same as rolling??

## RE: Plate Rolling Formula

It's not a formula until there's something on both sides of the equal sign.

## RE: Plate Rolling Formula

Regards

Mike

## RE: Plate Rolling Formula

Sorry for being late getting back, yes the bend formula works for rolling as well, when you roll a plate you are bending it on a large radius, the metal still has to shrink on the inside of the neutral line and stretch on the outside.To get a finished diameter that you want, you have to compensate by adding or subtracting part of the metal thickness from the neutral line.

B.E.