Cylinder Roll Length

[teb1]

As you get older you start to forget!

Would someone in this forum be kind enough to remind me as to what the formula is for figuring out the pre-roll cut length of a plate to be rolled into a cylinder of a specific diameter?

I am rolling a 2 1/4" thick plate to approximately 37.5" outside diameter. I want to end up with a 1/8 to 3/16" gap between the edges prior to welding.

As I remember it, there is a formula based on the inside dimension, and on the outside dimension for thick plates.

Any help would be greatly appreciated.

Thanks,

teb

 

[wjp123]

Hi teb1,

We calculate our mean diam = I/D + 8/9 plate thickness.
We have used this formula quite successful over the years.
Other workshops may have a different formula to calculate the shell length for rolling.
I hope this helps.
Cheers

 

[teb1]

Thanks for the quick response, but please clarify.

Please define "I" and "D" as used in the above formula.

Are you saying Cut length= pi x mean diameter + 8/9 x plate thickness?

mean diamter = (Outside Diameter + Inside Diameter)/2

Thanks,

teb1

 

[JStephen]

I think he means ID, not I/D. Cut length = (Inside diameter + 8/9 plate thickness) x pi.

We normally just figure to centerline of plate, but t/r ratio is much smaller than your example.

 

[wjp123]

Hi teb1,

Jstephen is quite correct. I/D should have been ID, We sometimes write things is little different in the land downunder.
Cheers

 

[teb1]

Thanks again for the responses.

The can thickness to Outside radius concerns me also. That is why I posted the question. When I get back home I am going to review some of my references to find the formula that we used to use. I don't recognize the one that was posted above.

Again, thanks for the quick responses.


Regards,

Tommy