Show HN: I made a knife steel comparison tool

Hi HN,<p>I’ve been collecting pocket‑knives for years, but every time someone asked “Is 20CV better than S45VN for corrosion?” I ended up hunting through scattered steel charts and forum posts. Last month I finally built a single‑page Knife Steel Explorer to scratch that itch.<p>What it is – A no‑login web app where you can filter 49 steels by corrosion resistance, toughness, edge retention, and ease of sharpening, then compare the ones you select in radar, bar, or scatter plots.<p>Why it’s different – Side‑by‑side data comes from peer‑reviewed metallurgy papers and CATRA tests and consensus as discussed from enthusiast websites, normalized to a 0‑10 scale so you can weigh trade‑offs visually instead of parsing spreadsheets.<p>How it’s built – React + TypeScript + D3 for the charts, all static files on Vercel with a simple express &#x2F; Typscript backend, so it should survive an HN hug‑of‑death.<p>Try it – <a href="https:&#x2F;&#x2F;new.knife.day&#x2F;steels" rel="nofollow">https:&#x2F;&#x2F;new.knife.day&#x2F;steels</a> (loads instantly, no signup, no tracking).<p>I’d love feedback on:<p>Is the 0‑10 scale intuitive or would you prefer raw units (HRC, g&#x2F;mm, etc.) in the main view?<p>What extra filters or metadata (price, country of origin, typical hardness range) would help your own knife buying or designing?<p>Any UI rough edges that stop you from exploring quickly?<p>Thanks for taking a look—happy to answer anything about the data set or implementation!