Abstract: A machining apparatus includes: a support mechanism that supports a workpiece; a cutting mechanism that cuts the workpiece that has been supported by the support mechanism; and a heat treatment mechanism that performs heat treatment on the workpiece that has been supported by the support mechanism. The heat treatment mechanism includes a coil that performs induction heating on the workpiece. The coil and the workpiece that has been supported by the support mechanism are movable relative to each other.

Abstract: An apparatus for manufacturing a rack bar includes a pre-forming machine forming a flattened portion on an outer peripheral surface of a hollow shaft member, a teeth forming machine forming rack teeth on the flattened portion, a heat treatment machine quenching the rack teeth, a first conveying machine carrying the shaft member into and from the pre-forming machine, a second conveying machine carrying the shaft member into and from the teeth forming machine, and a third conveying machine carrying the shaft member into and from the heat treatment machine. The first conveying machine, the second conveying machine, and the third conveying machine hold one end of the shaft member from a radially inner side of the shaft member. The apparatus of the rack bar are suitable for manufacturing a relatively short hollow rack bar having rack teeth formed over substantially an entire length of a shaft member.

Abstract: A rack bar includes a shaft member having a toothed section. The toothed section has a plurality of rack teeth, and extends over a portion of an entire length of the shaft member along a longitudinal direction of the shaft member. The shaft member has a grinding-finished outer peripheral surface extending over the entire length of the shaft member including the toothed section. A method for manufacturing the rack bar includes forming the toothed section by plastic working and grinding the outer peripheral surface to improve shape accuracy.

Abstract: A rack bar includes a shaft member having a toothed section. The toothed section has a plurality of rack teeth, and extends over a portion of an entire length of the shaft member along a longitudinal direction of the shaft member. The shaft member has a grinding-finished outer peripheral surface extending over the entire length of the shaft member including the toothed section. A method for manufacturing the rack bar includes forming the toothed section by plastic working and grinding the outer peripheral surface to improve shape accuracy.