淘汰一字形钎头

因一字形钎头破岩效率低和几何形状结构缺陷等问题，瑞典从７０年代中期就用锥体连接的十字和球齿钎头取代了一字形犴头。现在，我们建议用更具优势的复合片齿钎头逐步更新一字形钎头，新系列钎头寿命为一字，球齿钎头寿命的２－４倍，而价格仅比同直径一字，球齿钎头高１／５－１／３。

Eliminating Chisel Bit

Because of the lower rock fragmentation efficiency and defective geometrical shape of chisel bit, Sweden has replaced chisel bit with taper connecting cross chisel bit and button bit since the mid seventies. Now, we propose that chisel bit is renewed with more advantageous composite cutter bit gradually. The expected life of new series of bit is 2 to 4 times of that of the chisel bit and button bit, and the price is only one fifth to one third higher than that of chisel bit and button bit.