Steel Mast

halo guys.
this is my first thread in this forum. sry if i break any rule here..
ok... now im building steel hull 44ft sailboat in indonesia.
design by bruce roberts. the boat is voyager ds440.
https://www.bruceroberts.com/public/HTML/CUSTOM-440.htm

when im estimating building cost, aluminum mast is way over my budged.
in fact, it cost more then my steel hull construction. and importing aluminum goods is very hard in indonesia (bureaucracy and tax)
so.. it left me no other option to diy my mast form steel (because we dont have A6000 series aluminum or aluminum alloy for structure).

in design sail plan.
DESIGN RIGHTING MOMENT:86.000 FT-LBS
I tt: 20,0 IN^4 831 CM^4
ILL: 68,5 IN^4 2852 CM^4
YOU WILL NOT FIND AN EXACT MATCH OF THE SPEC'D INERTIAS, CHOOSE AN EXTRUSION THAT MEETS OR EXCEEDS THE HIGHER OF THE TWO NUMBERS, WHICH WILL USUALLY BE THE ILL NUMBER.

From this data, can anyone help me to how to design this mast section from steel alloy?
or how do aluminium mast manufacture select mast section form this data?

any information or guide for designing mast section really help me.
i try google it steel mast and come with empty (only blog or photo of construction steel mast)

PS. sry for my broken English. i hope you'll understand my point
thenk you

 

Are you building this with a fee to the designer or basing it roughly on one of their designs?

 

A reference could be boat building heretic by Brian Schwinn he covers Manufacturing aim steel mast from 5 inch tubing 8 inch wall