Haynes 200 description: HAYNES 200 RTW filler metal is used for the gas metal arc, gas tungsten arc and submerged arc welding of a variety of cast iron grades including gray, malleable and ductile. The weld deposits are easily machinable and can be deposited using a variety of processes. HAYNES 200 grade is equivalent to fi ller metal 99 grades and can be used to weld cast iron materials to a variety of carbon steels. The RTW filler metal fi nish on the spooled wire promotes smooth feeding through welding equipment and reduced tip wear in contact tips.