The steel mill is a facility that produces 1x [[steel]] every 35 seconds. [[Steel]] is used mainly for Construction Material rather than production input. The List of Buildings that use [[steel]] can be seen below.
You need 1/7th of a [[Coal Iron mine]] and 2/3 of an [[Iron 1 Coal mine]] can passively provide enough materials to maintain this factorysupport (1-2) steel mills.
You need Recommended build ratio is 4 Iron mine and 1 Coal mine for every 7 Steel mill. For every 50x production it'll have 1 excessive [[Iron]] and for every 5x production, it will have 3 excessive [[Coal]].</br>Excess material can be sold or stockpiled in case of bad regional modifiers. == [[Help:IdleCorp_Profit#Ratio|Ratio]] ==[[Help:IdleCorp_Profit#Minimum|Minimum]]: 1 [[Iron mine]] : 1 [[Coal mine]] and 14 : 1 [[Steel mill]]==== [[Help:IdleCorp_Profit#Meta_Ratio|Meta Ratio]] ====4 [[Iron mine]] with 21 : 7 [[Steel mill]] to produce without overdoing it</br>1 [[Coal mine]] : 7 [[Steel mill]] '''Disclaimer: The ratio above is for calculation only. The real value may vary. '''