This snippet may depreciated, please read https://gist.github.com/cydh/7b77580fc50b8f8b508c38dca296325a | Sample macro for Change Material skill after patching the https://gist.github.com/cydh/e1473eb2a242d221e80a42dce4ed7093. Change the Tsurugi [1] to Steel for simple lines!

[ok]cm_tsurugi2steel.txt

macro doConvSteel {
	$per = @eval($.weight * 100 / $.maxweight)
	# log \$per $per
	$count = @invamount (Tsurugi [1])
	while ($count > 0 && $per < 90) as loop
		do ss GN_CHANGEMATERIAL
		pause 2
		$idx = @inventory (Tsurugi [1])
		# log \$idx $idx
		do cm $idx 1
		pause 1
		$per = @eval($.weight * 100 / $.maxweight)
		$count = @invamount (Tsurugi [1])
	end loop

	:stop
		stop
}