Dragon Coin is a bench companion for anyone who hardens steel 🔥🔨: knifemakers 🔪, blacksmiths ⚒️, tool restorers 🛠️ and metalworking students 🎓. It turns heat treatment from guesswork into a repeatable, measured process 📏 — you plan a schedule from real metallurgical data 🧪, work the piece through each stage, and record the hardness you actually achieved so the next piece comes out better 📈.

Start from the steel library 📚: fourteen real tool steels, from simple carbon 1084 to high-alloy stainless 🧲, each with its austenitizing temperature 🌡️, soak time ⏱️, quenchant 💧, normalizing cycles 🔄 and a full tempering curve 📊. Pick a steel and the temper calculator 🧮 works backwards from the hardness you want 🎯, giving you the tempering temperature and time to get there, plus warnings ⚠️ about the traps that particular alloy is known for.

Every piece you make lives on the bench board 🧰 — a stage board that tracks it through forging 🔥, normalizing 🔄, hardening 💪, tempering 🌡️ and finishing ✨, so you always know what is waiting on you 👀. Photograph the workpiece 📸 at each stage straight from the camera or your gallery 🖼️ and the photos stay attached to that piece's record 📂. When it comes off the bench, log the measured hardness 📏 and the app charts your predicted-versus-actual gap 📉 over time, so you can see your process tighten up 🎯.

Everything is stored on your device 📱. No account ❌, no sign-in 🚫, no cloud ☁️.

Key features ✨:

Bench board 🧰: a stage-by-stage kanban 📋 of every piece in progress 🔄
Steel library 📚: 14 tool steels with full spec sheets 📄 and tempering curves 📊
Temper calculator 🧮: target hardness 🎯 in, tempering schedule 📅 out
Piece detail 🔍: stage timeline ⏳, spec plate 📄 and predicted-vs-actual hardness 📉
Photo record 📸: capture or pick workpiece photos 🖼️ at any stage, delete any time 🗑️
Log & stats 📊: hardness tests 📏, accuracy trends 📈 and per-steel performance ⚙️
Editable profile 👤 with avatar 🧑‍🎨, fully offline 📴, no account required 🚫