Grindstones and Other Sharpening Media

Selecting a wheel for your Tormek machine can be confusing. Sharpening Supplies spoke with Stig from Tormek to help you understand the differences between the different wheels available.

In this episode we go through the basics of one of the most important parts of the sharpening process – honing. Honing your edge after sharpening will deburr your edge, which is crucial to get it sharp and durable. In addition, it polishes the edge to give cleaner cuts.

But honing is also a means of maintenance for your edge between sharpenings. Many times, a couple of strokes on the honing wheel is all you need to get that razor sharpness back again. That will save both time and steel!

Key Note: At just past 18 minutes in the video, there are great microscopic pictures showing the effect of different grindstones on the ground surfaces. This is a great comparison of the various Tormek grindstones, but also about typical bench stones and CBN wheels also.

For todays special episode, Sebastién speaks with Håkan, a real abrasive expert who also happens to be the CEO of Tormek. Together they dive into the details of the Tormek Diamond Wheels (DC-250, DF-250, DE-250). They also discuss the most frequently asked questions about sharpening with diamonds.

• Tormek Diamond Wheel options
• The development of the wheels
• The structure of the Diamond Wheels
• Steel core vs. Aluminium
• Life span
• Pressure and run-in period
• Why diamond instead of CBN?

Tormek LA-220 Leather Honing Wheel

Tormek LA-120 Profiled Leather Honing Wheel

Tormek CW-220 Composite Honing Wheel

• +2° is recommended for optimal stropping. The backs of chisel blades are often honed by hand, though jigs are also recommended for other edges as +5° will start to round over the edge.
• When in doubt, follow Wootz' rule, "the softer the steel, the higher the angle". Really hard steels could have this decreased to +1.2°.

Tormek SJ-250 Japanese Waterstone

Tormek DE-250 Diamond Wheel Extra Fine

• Finely honed edge from this stone is especially useful for finishing cuts
• Use a diamond grinding wheel for tools with vanadium levels >3%.
• Do not use diamond wheels for tools with ferrous metals unless they are cooled (e.g., with water). Hot iron molecules can dissolve diamonds, quickly eroding the surface.

• 3,000 grit ProEdge Trizact Belt

Razor Sharp Edgemaking Paper Wheels

• A common rule of thumb is "Better to do two quick passes than one slow one" to minimize edge softening with heating.
• I use the 8-inch wheels on a 6 inch grinder.

Very high grit (800+) CBN

• Use a CBN grinding wheel for tools with vanadium levels >3%.
• Most CBN manufacturers recommend not using the CBN wheel with water. It can invalidate the warranty.
• CBN wheels are not recommended for tools with high carbon steel. Those and other softer steels can "gum up" the wheel's surface. That said, a person I cannot remember has stated that grinding high speed steel (HSS) on the CBN wheel will clear the "gumming".
• Resins accrued on tools when turning wet woods can also gum up the grit. Trend lapping fluid was recommended (on an AAW forum) by Reed Gray (aka, "Robo hippy") for cleaning the wheel.

Tormek SB-250 Black Grindstone

• Use for harder steels like HSS
• Grade to 220 grit for initial sharpening, especially if the tool needs a bit of work.
• Grade to 1,000 grit for final touch-up on sharpening, especially for tools which won't be honed.

Tormek SG-250 Original Grindstone

• Use for high carbon steel
• Grade to 220 grit for initial sharpening, especially if the tool needs a bit of work.
• Grade to 1,000 grit for final touch-up on sharpening, especially for tools which won't be honed.

Tormek DF-250 Diamond Wheel Fine

• Good all-round wheel which leaves a smooth surface finish
• Use a diamond grinding wheel for tools with vanadium levels >3%.
• Do not use diamond wheels for tools with ferrous metals unless they are cooled (e.g., with water). Hot iron molecules can dissolve diamonds, quickly eroding the surface.

Sorby ProEdge System

120 grit ProEdge Zirconium Belt

Pedia ProEdge Diamond Belt

600 grit ProEdge Trizact Belt

1,200 grit ProEdge Trizact Belt

• Be sure to manage the temperature so that the temper is not lost due to overheating.
• If there is a carbide insert, then DO NOT cool by dipping in water. This will cause the carbide to crack due to shocks. Otherwise, dip it frequently in water.

150 - 180 grit, very friable grindstone, such as aluminum oxide

• Friablility reduces (but does not eliminate) the heat build-up. Be sure to manage the temperature so that the temper is not lost due to overheating.
• If there is a carbide insert, then DO NOT cool by dipping in water. This will cause the carbide to crack due to shocks. Otherwise, dip it frequently in water.
• Truing the stone may be necessary.
• 80 grit silicon carbide (green) is recommended for tools with carbide inserts, and especially for stone carving tools.

150 - 180 grit CBN

• Use a CBN grinding wheel for tools with vanadium levels >3%.
• CBN wheels are not recommended for tools with high carbon steel. Those and other softer steels can "gum up" the wheel's surface. That said, a person I cannot remember has stated that grinding high speed steel (HSS) on the CBN wheel will clear the "gumming".
• Resins accrued on tools when turning wet woods can also gum up the grit. Trend lapping fluid was recommended (on an AAW forum) by Reed Gray (aka, "Robo hippy") for cleaning the wheel.

150 - 250 grit

• Be sure to manage the temperature so that the temper is not lost due to overheating.
• If there is a carbide insert, then DO NOT cool by dipping in water. This will cause the carbide to crack due to shocks. Otherwise, dip it frequently in water.

Tormek SB-250 Black Grindstone

• Use for harder steels like HSS
• Grade to 220 grit, and re-grade often.
• Truing the stone may be necessary, depending on the amount of grinding needed.
• Use when the area to be ground is not great.

Tormek SG-250 Original Grindstone

• Use for high carbon steel
• Grade to 220 grit, and re-grade often.
• Truing the stone may be necessary, depending on the amount of grinding needed.
• Use when the area to be ground is not great.

40 - 80 grit grindstone, such as aluminum oxide

• Truing the stone may be necessary.
• Management of the temperature is not critical as the speed is slow, and the process is also water cooled.

Tormek DC-250 Diamond Wheel Coarse

• Use a diamond grinding wheel for tools with vanadium levels >3%.
• Do not use diamond wheels for tools with ferrous metals unless they are cooled (e.g., with water). Hot iron molecules can dissolve diamonds, quickly eroding the surface.

• Be sure to manage the temperature so that the temper is not lost due to overheating.
• If there is a carbide insert, then DO NOT cool by dipping in water. This will cause the carbide to crack due to shocks.
• Otherwise, dip it frequently in water.

<100 grit, very friable grindstone, such as aluminum oxide

• Friablility reduces (but does not eliminate) the heat build-up. Be sure to manage the temperature so that the temper is not lost due to overheating.
• If there is a carbide insert, then DO NOT cool by dipping in water. This will cause the carbide to crack due to shocks. Otherwise, dip it frequently in water.
• Truing the stone may be necessary.

<100 grit CBN

• Use a CBN grinding wheel for tools with vanadium levels >3%.
• CBN wheels are not recommended for tools with high carbon steel. Those and other softer steels can "gum up" the wheel's surface. That said, a person I cannot remember has stated that grinding high speed steel (HSS) on the CBN wheel will clear the "gumming".
• Resins accrued on tools when turning wet woods can also gum up the grit. Trend lapping fluid was recommended (on an AAW forum) by Reed Gray (aka, "Robo hippy") for cleaning the wheel.

<150 grit

• Be sure to manage the temperature so that the temper is not lost due to overheating.
• If there is a carbide insert, then DO NOT cool by dipping in water. This will cause the carbide to crack due to shocks. Otherwise, dip it frequently in water.