A
tungsten steel cutter which is lower cost to use and can increase fabrication efficiency and improve quality mainly includes a shank and a bit screwing at a front end of the shank. Both are made of
tungsten steel and formed in an integrated fashion. The shank has a screw hole at the front end and a
coupling trough formed at the front end of the screw hole. The bit has a screw bar extended from the bottom end thereof and a
coupling neck at the front section of the screw bar. The
coupling trough is formed at a depth same as the height of the coupling neck and the coupling trough and the coupling neck are formed at the same size. The bit and the shank have respectively a
water discharge passage and a water drawing passage, and a
water intake passage that communicate with each other. The
water intake passage is formed at a greater
diameter than the
water discharge passage and water drawing passage. Thus when the bit and the shank are screwed together, in addition to screw coupling of the screw hole and the screw bar, the coupling trough and the coupling neck also form a tight coupling to minimize gaps that might otherwise happen between them like the conventional ones do. The
water discharge passage and
water intake passage provide
cooling effect for
cutting fluid and prevent debris from accumulating on the bit and affecting
cutting quality. The invention provides a two-section coupling that can save the cost and improve steadiness and fabrication efficiency of precision tools.