Abstract: The present invention provides a brazing filler metal whose brazing temperature is 1060-1120° C. which is close to that of BNi-2 specified in JIS Z3265. The present invention also provides a brazing filler metal which has a melting point of 890-980° C. (which is close to that of BNi-7) and is capable of brazing at a temperature lower than 1000° C. The brazing filler metal of the present invention improves the base metal in corrosion resistance without deterioration. In addition, it has good resistance to oxidation and good resistance to corrosion by sulfuric acid. It has high strength, good heat resistance, and good wetting characteristics. It is used to produce durable EGR coolers by brazing. The first brazing filler metal is composed of Cr (20-30 wt %), P (3-10 wt %), Si (2-7 wt %), and Ni (remainder). It may be incorporated with another brazing filler metal composed of Cr (10-15 wt %), P (7-12 wt %), and Ni (remainder) in an amount of 2-15 wt %.

Abstract: A valve operating push rod for an internal combustion engine comprises a metal tube having end members with outer hardened surfaces of arcuate shape welded to the respective ends of the tube. A tubular metal member having a length slightly shorter than that of the tube is pressure fitted inside or outside the wall of the tube. At least one of the ends of the tubular member is spaced apart from the welded portion between the tube and the corresponding end member. The problem of vibration between the valve head and valve seat of the intake or exhaust valve of the engine can be minimized in this way due to the different individual vibrations of the tube and tubular member, since at least one end of the tubular member is not in contact with the corresponding welded portion.