Review on 🔪 Precision Leather Cutter: 0.5mm to 5mm Cutting Tools for Working with Plastics by Samuel Lewis

My set was useless for punching clean holes. I was able to hand sharpen them on a set of small diamond blades (any sharpening stone/blade will do), after which they worked very well. If you have the means to sharpen them (and more time than money), then go for it. Otherwise I would have spent a little more for a higher quality set. FWIW, I consider myself a newbie to sharpening and was able to get them up to a good level of sharpening with ease. They sharpen quickly so I doubt it's hardened steel, but if you're just punching through leather and other soft materials it probably doesn't matter.