A blade or a razor don't work in the same way as a needle. Why ? Because the needle creates vacuum conditions inside, and air does not penetrate an in case the needle contains some infected blood, as pressure keeps the air outside, HIV is still able to infect once injected to another person. A razor, a blade, or any other equipment used in a beauty saloon don't have any structure that could keep blood inside, isolated from air, and keeping the virus able to infect. If these places where normal sources of HIV, we would see millions of new infections every single day, and we don't see them.
The only ways HIV is spread are:
-Unprotected vaginal/anal penetrations.
-Sharing needles to inject drugs.
-mother to child.
All the best.