S Series Chicago/Steelcase keys by the code number. First key cut from provided code number (Precut Key). Chicago Lock has provided locks for many OEM applications, such as Steelcase and others for many years. Standard Chicago/Steelcase Code Series: S100-S200. Keys engraved with key code number. One code cut is required for each different key number you would like to purchase - extra cut keys may be duplicated from the code cut key and purchased at a discount.