Kanthal, nichrome, and stainless steel all have different resistance characteristics. Stainless steel, for example, changes resistance as it heats, which is why it's used in temperature control. Nichrome has a different resistivity than kanthal, so the same wrap count will give you a different ohm reading.

If you're listing coils on your site, you need to specify the material, gauge, and wrap count so customers know what they're getting. Saying "0.3 ohm coil" isn't enough if you don't mention it's a 3mm ID, 6-wrap kanthal build. That level of detail builds trust and reduces returns.