REGRINDING MANUAL FOR SOLID CARBIDE DRILL MWE / MWS type April 30, 2009 MITSUBISHI MATERIALS CORPORATION CARBIDE & TOOLS DIVISION
Checking conditions of the cutting edge • Check wear conditions of and damage to the cutting edge. • If there is serious damage such as fracture on the cutting edge, grind the edge until the damage is all gone. Grinding first relief face • Fig.1 Install the drill by using collet chuck. As shown in fig.1, set the drill phase in order that the corner of center cutting edge and Horizontal the shoulder of outer peripheral edge become parallel to each other when seen from the top. • Fig.
• Grind until lip height difference (axial runout of front cutting edge) is 0.02mm or less. Grinding second relief face • Fig.4 After grinding first relief face, grind second relief face. • As shown in fig.2 of the previous section, keep rotation angle of the drill (work head) at 20°. 23°～27° • As shown in fig.4, set inclination angle of the drill (work head) at 23°~ 27°. If inclination angle of the drill (work head) cannot be increased to 23°~27°, get the 15° wheel inclined 15°as shown in fig.
Grinding thinning face • After grinding second relief face, grind thinning face. Type of the thinning is Height gage X-thinning. • First, set the work head horizontal so that the center of the drill will be horizontal. Drill rotation angle is 0°. Set the direction of table oscillation parallel with the center Fig.7 line of the drill. • As shown in fig.7, set the drill phase so that the line connecting the shoulder of both sides will be horizontal by using a device such as height gage. • Fig.
• －0.03～0.03 Adjust the wheel position while grinding so that the measurements of the thinning (X part, Y part) will be the same as those of fig.10. (Dotted lines show the final positions. Y part • (Grinding tip) To make the task easy, grind the two cutting edges alternately, using a mirror to check the configuration while grinding. 0.1～0.2 X part Honing • Fig.11 After grinding thinning face, grind honed edges. This is the last procedure for R（0.1～0.15）×φD） regrinding.
This is the end of regrinding. Please ascertain that all the following specifications are fulfilled before using WSTAR drill again. • Lip height difference (axial runout of front cutting edge) < 0.02mm • There is no damage left on the cutting edge. • Appropriate honing is applied to the edge. • There is no grinding burr.
