How long does a safety razor blade last well it can be up to 5-7 close, and comfortable, tug-free shaves, due to its sharpness and that you can use both sides of the safety razor. For best results change the blade at least weekly to guarantee for a close shaving experience and for the price of the blades avenging 25p it is so much more affordable than the better-known brands and it is environmentally friendly as it's just a piece of metal all double edge blades fit any Safty razors.