Material selection is a critical decision with any knife. All materials have slightly different characteristics that we take into account when suggesting a material to our customers. Some are quite obvious, such as toughness and wear resistance, but others might not be so apparent. Plus we have to decide how changing one characteristic affects the other characteristics that are important. Here is a list of all we consider:
What type of wear? A sliding wear or a more direct type of erosion? Many times corrosion looks like erosion, to the untrained eye.
Does the knife need flexibility or the ability to “give”? Is impact toughness needed? Is there any side-loading?
What environment is the knife operating in? Is it a food application? Is some surface rust allowed? How long is the knife expected to run? Some knives are changed well before any corrosion has time to occur.
Sometimes a certain material may be optimum for an application, but is so difficult to acquire that we will avoid it.
Is the cost per machine hour such that it is worthwhile to spend more money on expensive material that will last longer? How long does it take to change the knives?
What are the special features of the knife that will be difficult to machine and thus raise the costs of certain materials?
Quality of Cut
How important is the quality of cut? Is a knife material needed that will allow for ultra-sharp edges?
Does a higher hardness cause a potential problem when running against another part that is also hardened? Which one is less expensive or easiest to change and thus should be the “sacrificial lamb”?
With 50 years of knife manufacturing experience, we are experts at helping you choose the best performing material for your knives. We invite you to talk to one of our Sales Engineers about your application!
The chart below lists most of our more popular raw materials along with how they compare with each other in terms of: Wear Resistance, Toughness, Cost and Availability. We have made products out of many different materials not listed including Copper, Diamond, Sapphire, and Aluminum.
|STEEL SELECTOR 1 = Low 10 = High|
|CERAMIC||10||1||10||2||VERY EXPENSIVE IN SMALL QTYS AND LARGER KNIVES. OFTEN A DIE CHARGE – VERY BRITTLE. COSTLY TO MACHINE.|
|TUNGSTEN CARBIDE||9||1-3||9||9||GRADES CAN BE MADE TOUGH TO VERY BRITTLE, AS NEEDED. SIZE OF GRAINS MATTER. COSTLY TO MACHINE.|
|FERRO-TIC||7.5||2||9||4||MACHINEABLE CARBIDE. WAS POPULAR BUT OFTEN BEING REPLACED BY POWDERED METALS SUCH AS CPM’S*.|
|CPM*-15V||8.5||2||8.5||3||POWDERED METAL. HIGH WEAR RESISTANCE BUT WATCH OUT IN ANY IMPACT TOUGHNESS SITUATIONS.|
|CPM*-10V||8||3||8||7||POWDERED METAL LIKE 15V, BUT SLIGHTLY LESS IN WEAR. MORE POPULAR AND AVAILABLE.|
|M-42 HSS||7.5||3||7||3||HIGH SPEED STEEL. HIGHEST WEAR RESISTANCE IN HIGHER HEAT APPLICATIONS.|
|M-4 HSS||7||3||7||4||HIGH SPEED STEEL. GOOD WEAR RESISTANCE IN HIGH HEAT APPLICATIONS.|
|A-7||6.5||4||5||3||LOWER COST ABRASION RESISTANT STEEL USED IN MANY CASES WHERE POWDERED METAL IS TOO COSTLY.|
|CPM*-3V||6.5||8||8||6||POWDERED METAL WITH VERY GOOD TOUGHNESS AND HIGH WEAR RESISTANCE.|
|M-2 HSS||6||4||5||8||HIGH SPEED STEEL. MOST POPULAR HIGH SPEED STEEL BUT SLIGHTLY LESS WEAR RESISTANT. MORE AVAILABLE.|
|6||7||3-6||7||GREAT COMBINATION OF WEAR RESISTANCE AND TOUGHNESS. GOOD FOR RECYCLING KNIVES|
|D-2||5||5||2||10||OUR MOST POPULAR AND AVAILABLE STEEL. ESPECIALLY LOW COST IF YOU CAN WAIT 5 MONTHS FOR STEEL.|
|A-2||4.5||7||2.5||8||SIMILAR TO D-2 BUT NOT AS POPULAR. CAN OFTEN SUBSTITUTE D-2 AND LOWER COST WITH NO LOSS IN PERFORMANCE.|
|MOD. A-8||4.5||8||2-3||8||CHIPPER KNIFE STEEL. NEAR D-2 BUT A BIT TOUGHER. D-2 IS MORE AVAILABLE AND SOMETIMES LESS COSTLY.|
|H-13||4||8||4||6||SHOCK RESISTING ALLOY STEEL. GOOD TOUGH STEEL IN HIGH HEAT APPLICATIONS.|
|S-7||4||9||4||5||SHOCK RESISTING ALLOY STEEL. TOUGHEST STEEL WE COMMONLY USE FOR KNIFE APPLICATIONS.|
|440-C SS||4||5||4||8||MOST WEAR RESISTANT STAINLESS STEEL. GOOD FOR CORROSIVE APPLICATIONS.|
|420 SS||3.5||5||3.5||8||SLIGHTLY LESS WEAR RESISTANT THAN 440-C BUT LESS EXPENSIVE AND OFTEN MORE AVAILABLE.|
|L-6||3.5||8||2||6||GOOD, STANDARD ALLOY STEEL. OFTEN USED IN PLACE OF O-1 OR 52100 FOR STRAIGHT KNIFE APPLICATIONS.|
|STELLITE||3||8||10||8||VERY EXPENSIVE, OFTEN INLAID – BEST CORROSIVE RESISTANT STEEL. VERY LUBRISTIC TYPE OF STEEL.|
|S-5||3||8.5||3.5||5||SHOCK RESISTANT ALLOY STEEL. A TOUGH STEEL SOMETIMES LESS COSLTY AND MORE AVAILABLE THAN S-7.|
|52100||3||5||2||7||OFTEN CALLED BALL BEARING STEEL. LOW COST IN CERTAIN SIZES. MOST OFTEN USED FOR CIRCULAR KNIVES.|
|4140||1.5||6||2||7||ALLOY STEEL. QUITE TOUGH AND THUS GOOD FOR LARGE, SCRAP OR SHREDDER TYPE KNIVES.|
|5160||2.5||6||1||4||VERY LOW COST STEEL FOR NON-DEMANDING APPLICATIONS. SUSCEPTIBLE TO CORROSION.|
|SK-5||2||5||2||8||CARBON STEEL, OFTEN USED OVERSEAS FOR STANDARD KNIVES. VERY SIMILAR TO 1095 BUT SLIGHTLY LESS CARBON.|
|1095||2||5||2||8||CARBON STEEL QUITE POPULAR IN THE USA FOR LOW COST KNIVES. ALSO AVAILABLE IN OTHER CARBON GRADES.|