Pipe cutters have a single wheel blade that cuts the metal piping when the cutter is turned. The wheel is usually made from hardened steel.
Hardened steel
Hardened steel is steel that has been heat treated to make it tougher and more resistant to wear over time.
It is important that pipe cutter wheels are strong so that they can cut through metal piping. As the tool is made to be used a number of times it also needs to be resistant to wear. If the wheel becomes dull quickly it will not cut through the pipe, and instead will just score it.
Hardening steel can make the metal very brittle so it needs to be tempered straight afterwards to counteract this.
How is steel hardened and tempered?
Step 1
Heat the piece of steel to be hardened gradually until it reaches a high temperature.
Step 2
Apply a great heat intensity to the area that needs to be particularly hardened. In the case of pipe cutter wheels, this is the edge around the wheel which will become the cutting wheel.
Step 3
When the intended area turns red (at a temperature between 600°C and 800°C) remove from the heat and place the steel into a pot of cool water.
Step 4
Now that the steel has been hardened, it needs to be tempered. This is done by reheating the intended spot until it turns blue (around 300°C).
Step 5
Finally leave the piece of metal to cool on its own.