An Etymological Dictionary of the German Language/Stahl
Stahl, m., ‘steel,’ from the equiv. MidHG. stahel, m. and n. (contracted stâl, with the variant stachel), OHG. stahal (stâl, *stahhal); corresponding to Du. staal, AS. stŷle, steli, n., E. steel, and the equiv. OIc. stâl (Goth. *stakla-), n. A pre-Teut. form staklo- is implied by the cognate OPruss. stakla, ‘steel.’ Other corresponding terms are wanting in the Aryan languages (so too in the case of Geld and Silber the Teut. terms are related only to the Slav.).