Avoid blades with rust or deep "pitting" (small holes eaten into the steel) on or near the cutting edge. As a rule of thumb, the blade should be clear of rust at least 3mm above the edge to allow for future sharpenings.
Look at the "spine" (the thick top part of the blade). If it has a large, flat, uneven area, it indicates the razor has been excessively or poorly sharpened and may be near the end of its life. how to buy a vintage straight razor
The blade should be straight and not "warped" or "smiling" excessively (unless it was designed with a curved edge). 2. Inspecting the Scales (Handles) Avoid blades with rust or deep "pitting" (small
Tips for Buying a Vintage Straight Razor - Kent of Inglewood If it has a large, flat, uneven area,
The blade's condition is the most critical factor. Many aesthetic flaws can be polished out, but structural damage often makes a razor a "lost cause".