Grinding M-2, Karbo Krome^® KNIVES
When grinding moulder and planer knives, factors such as grinding wheel types and grit are often a matter of personal preference. A grinder operator may be able to get the same results using different abrasives by altering the RPM of the wheel and the rate of feed. There are, however, some important guidelines that should be followed in order to guarantee the safest and best results. Always be sure to read the operation instructions for your grinder as well as any information from the manufacturer of your abrasives and grinding wheels. Be sure to observe all safety instructions with regard to protective devices and proper ventilation.

Whether you choose to grind using a single wheel, or you rough grind with a coarse wheel followed by a finish grind with a finer wheel, the quality of the knife bevel that you produce will play an important role in your success and the quality of your moulding. Generally, a 35 degree bevel on the knife itself will give the best results for most planing or moulding applications using M-2 High Speed steels or Karbo Krome^® (D-2).  On most profile grinders, this is obtained by setting the clearance angle on the grinder at either 40 to 35 degrees for a 10 degree hook angle head or by setting the clearance angle to 30 to 25 degrees for a 20 degree hook angle head.

The RPM for your grinder should be as recommended by the grinding wheel and grinder manufacturer.

Grinding Opti^® Knives
When using WKWs exclusive OPTI knife, the procedure is the same as on regular steel knives with a couple of exceptions.  The best results are achieved when the knife is ground to a 45 or 50 degree bevel, or in other words, a more "blunt" bevel that leaves more knife material at the cutting edge.  On most profile grinders this is obtained by setting the clearance angle on the grinder at either 35 to 30 degrees for a 10 degree hook angle head or by setting the clearance angle at 25 to 20 degrees for a 20 degree hook angle head.

In addition, it is important to be careful not to chip the cutting edge on the OPTI knife because it is much harder than conventional tool steels. A better finish will be obtained on OPTI knives if the grinding wheel RPM is increased by 200 RPM above the RPM used for normal tool steels for the rough and finish grind.  Be sure to check with your wheel manufacturer and never exceed maximum recommended RPM.

Never grind or hone the face on OPTI knives as this may remove the ultra hard surface of the knife.

Grinding the BAK PAK^® Carbide Knife System
Always be sure to read the operating instructions for your grinder as well as any information from the manufacturer of your abrasives and grinding wheels.  Be sure to observe all safety instructions with regard to protective devices and proper ventilation.

Before attempting to grind the knives, be sure that you have properly balanced the carbide and backer knife blanks.  Balancing is accomplished by balancing the carbide blank and the steel backer together; not as individual pieces.  When necessary, grind material off the steel backer rather than off the carbide.  Adequate balancing is attained when the knives weigh the same or are less than 1/10th of a gram apart in weight.

The BAK PAK^® carbide knife system is best ground in two steps. The steel backer is first ground to the profile in the same manner that you would grind a steel knife. The carbide blank is then located into the head and ground to the profile.

Best results are obtained with a bevel of 45 to 50 degrees on the carbide with a bevel on the steel backer of 35 degrees. Grinding the carbide blank to an angle sharper than 45 degrees will produce a cutting edge that will be prone to chipping and premature wear. Several regrinds of the carbide are possible before the blank must be relocated into the next groove.

Jointing may be accomplished by using a 150 - 230 grit aluminum oxide stone. Be sure to follow the machinery manufacturers recommended procedures.