The handle is made of polymethyl methacrylite. I know this because it is stiff, hard and brittle, just some of the features of this plastic. It is cheap and easy to manufacture, but also durable and light to hold. It is quite comfortable to hold. At the end of its life you could recycle it quite easily.👍🏻
The springs are made of coiled hardened steel because it allows it to be strong without being brittle. Also, this type of spring could be manufactured for all sorts of things, not just staplers which makes it cheaper and more versatile to produce. The springs allow the stapler to move and push the staples out.
The staples themselves are made of zinc-plated steel wires that can be pressed together and bent into the shape and size of staples. this is because it is strong and malleable(able to be pressed into shape without breaking) - useful for when the staple comes out.
This is the metal plate which bends the staples into shape as they are pressed out. I think is made stainless steel because it is hard and tough, resistant to wear and corrosion. It is a very important part of the stapler.
This is the place where you insert the staples and where you can take them out of. I think it is made of stainless steel because it is hard and tough, resistant to wear and corrosion. At the end of its life it would be difficult but not impossible to recycle.
This is a bolt that I think is made of stainless steel because it is hard and tough, resistant to wear and corrosion. It would join three of the different parts together in this product.