how do I make rotary cutter blades?

[moerman]

I have to make a number of rotary cutter blades of about 20 mm diameter. It is to construct a series of rubber cutters for cutting rubber motors for model flying. I can buy these blades for 30$ per pair but that is not my intention. For accurately cutting rubber the cutters must be very sharp. The blades must have a bevel on one side only and the pair will act like an endless scissors. In the attached picture the blades have a step grinded in the other side of the blade, but I hope to avoid this.

My method:
I have a lathe, toolpost grinder and drill press. I think it will be easier to start from flat plate and I am thinking of carbon steel from old hand saws.
As parting with my lathe still is risky bussines I rather not use carbon steel rod to make the cutters.
I can cut pieces from the saw plates and turn washers from them. Then I have to harden and temper them. And finally I have to sharpen them using a toolpost grinder.

My questions:
- are carbon steel disks or washers available so I can ommit the first steps?
- are there other alternative materials which are better or as good as carbon steel?
- is my method likely to give good results?

 

[toolznthings]

Look up rotary slitting knives. Several manufactures such as Dusenbery circular slitting knives.

 

[moerman]

Thanks! That helped me to search the internet for suitable parts. Although I didn't find the type of blades I'm after (single sided bevel, about 20 mm diameter) it did point me to a type of cutter I can use to cut disks out of carbon steel. Now I have to decide to buy this tile cutter or make my own version. How would such a cutter be called in machinist terms?

 

[Jasonb]

It would be easier to make the central hole first by drilling and reaming. Then rough cut out the parts, bolt a stack onto a mandrel and then turn the OD. not forgetting to anneal the blades before starting.

Gauge plate (ground flat stock) would be the raw material if you don't have suitable old saw blades

 

[neubert1975]

i am often using a bi metall hole saw, to cut steel discs. one like the on in attached image.
it works really well