machining, the aluminum content in Alloy Z may be beneficial for machining wood. On the other hand, Matrix II and Vasco Wear are low in tungsten and have high mean tool forces at the high hardness heat treatment. Improved M42 is also low in tungsten but the high cobalt content improved the wear resistance, most likely because cobalt increases hot hardness. Further, M42 exhibits better wear resistance than some of the HSSes at the low hardness heat treatment. Consequently, the alloying elements, their percentage of the steel, and the heat treatment are all important for extended tool life.
The general relation between hardness and tool wear is shown graphically in Figure 1. Low and high hardness heat treatments of HSSes are plotted versus 1/X, where X is the mean normal force, along with the standard deviation. A higher 1/X indicates longer tool life. The plots indicate exceptions to the direct relation between hardness and wear resistance. This reinforces the conclusion that the grade of HSS and the heat treatment are both important in wood machining.
but have different toughness values because of different temperatures in heat treating. The HSS microstructure and mechanical properties should be checked after heat treating knife stock or tools such as router bits to ensure proper heat treating.
Because M2 and M42 performed
about the same and slightly better than T15 and other alloys after the high hardness heat treatment, M2 should be an economical selection for tool steel when properly heat-treated. If tool steels perform equally in a wear test, the least expensive steel can be selected. ◻
Wear resistance
The nominal mechanical properties indicate that M42, M4 and T15 have much better abrasive wear resistance than M2. However, wear tests in this study show that M2 resists wear during wood machining equally or slightly better than any of the HSSes tested. Consequently, mechanisms other than abrasion cause tool wear when machining wood products. As shown in previous research, mechanisms such as high temperature corrosion/oxida-tion affect tool wear.
The proper heat treatment accurately applied to the HSS is as important as the selection of the HSS. For example, two pieces of M2 could be heat treated to the same hardness
THRIVING ON INNOVATION
TSS Tablesaw
10" or 12" Blade Capacity 3 to 5-hp Baldor Motor Heavy-duty Sliding Table
56" Crosscut Capacity
Euro-style Fence System
Optional Scoring w/ Separate Motor
Specification subject to change. Machine may be shown with optional accessories.
TS Tablesaw
10" or 12" Blade Capacity
3 to 5-hp Baldor Motor
50" Rip Capacity
Euro-style Fence System
Optional Scoring w/ Separate Motor
References:
Archives