The invention relates to a hard
alloy saw chain of a
chain saw. The
welding face of a hard
alloy tooth block and
cutting teeth is made to be a cylindrical face, the arc
radius of the cylindrical face is 2 to 5mm, and the optimal arc
radius is 2.5 to 4mm. The shape of the tooth block is made to be similar to a
frustum of a
square pyramid, and the height of inner side face of the teeth block is lower than the height of outer side face of the tooth block. The tooth side face of the tooth block concaves inwards and perpendicularly, and a concave angle is 1 degree to 3 degrees. The intersection of the tooth top face of the tooth block and the tooth side face of the tooth block is made to be a circular bead, the tooth tip of the tooth block is made to be a section of arc line, the arc
radius of the tooth tip is 0.2 to 0.8mm, and the optimal arc radius of the tooth tip is 0.3 to 0.4mm. According to the hard
alloy saw chain, due to the adoption of
butt welding, the hard alloy tooth block is welded with the
cutting teeth, after the tooth block is welded, local high-temperature
tempering is conducted, the joining strength of a
welding line is 4 times higher than the jointing strength of
brazing, the hard alloy saw chain is very firm, and no teeth drop during saw
cutting.