Method and Apparatus for fabricating a spacer frame for use in an insulating glass unit. One of a multiple number of possible spacer frame materials is chosen for the spacer frame. An elongated strip of the material is moved to a notching station where notches are formed at corner locations. The character of the notches is adjusted based on the selection of the metal strip material and more particularly to achieve bending of the material in an repeatable, straightforward manner. Better control over the notching process is also achieved by exhaust flow control of a double acting cylinder. A positioning spacer achieve very accurate side to side positioning of a die and anvil to precisely notch and deform the metal strip. Downstream from the notching station the metal strip is bent into a channel shaped elongated frame member having side walls. Further downstream a leading strip of channel shaped material is severed or separated from succeeding material still passing through the notching and bending station.