Stainless steel straight razors are unjustly relegated to a second-class reputation among many razor enthusiasts and users. However, the differences compared to carbon or mild steel, which are prone to rust, can be minimized through proper steel selection and optimal heat treatment by the manufacturer, even yielding some specific advantages. According to German industrial standards (DIN), a steel may be labeled "stainless" if it contains at least 10.5% chromium. Even a steel labeled "stainless" can rust if subjected to grossly improper use.
Improper use in this sense would include, for example, leaving fruit acids on the blade after use. However, simply wiping the knife dry is sufficient in most cases to prevent corrosion. Experts outside the trade therefore usually and correctly refer to "rust-resistant" steel. This term will be used here for the sake of accuracy. To obtain a rust-resistant blade, the addition of chromium to the alloy is essential. Chromium also has the property of making the steel's microstructure coarser—and to a considerable extent. This is generally undesirable for a cut requiring pressure, such as wet shaving. This difference is visible under a scanning electron microscope and makes a dramatic impression, but is hardly noticeable in practical use. In return, one gains the considerable advantage of rust resistance.
One limitation is that straight razors made of stainless steel are less suitable for beginners. Because stainless steel is more brittle, it reacts less well to wear and deformation. Even though stainless steel blades can ultimately be brought to a similar sharpness, stropping and honing require a bit more practice. Stainless steel straight razor blades reach their full potential when they are moved across the skin with a very slight offset, i.e., with a very gentle sideways pull. The slightly coarser edge then creates a microscopic sawing effect. However, this technique should only be used by very experienced users, as it can only be mastered with considerable practice. In conclusion, purchasing a stainless steel straight razor can be highly recommended for experienced users when traveling or for everyday use with limited time.