We use Swedish stainless steel blades which are honed to a microscopically thin edge to give a clean, smooth shave. Each blade should last 7-10 shaves, depending on how coarse your hair is and how much surface area you are shaving. If you have very coarse hair, it may be more like 4-6 shaves. However safety razor blades have the same 'shave life' as your plastic razor, so whatever you currently get from that, will be the same with a safety razor. When you start feeling that 'dragging' sensation, then you know it's time to change the blade.