4J29 specification:plate,sheet,strip,rod,bar,wire,tube,etc. Looking forward to cooperating with you! 4J29 KOVAR4J29 is also known as kovar alloy,ASTM F15,Nilo-K, UNS K94610 ,(FeNi29Co17),YB/T5231-2005 ,(FeNi29Co18),Lockinvar,Alloy 12B,Sealing Alloy. Iron Nickel cobalt. Note:A Nickel-Iron-Cobalt, controlled expansion alloy containing 29% Nickel. It's coefficient of expansion (which decreases with ...