Fornax: Steel Heat Colors

The heat-color chart, off the forge wall and into your pocket.

Every smith knows the old printed color chart taped up by the forge - the one that says what "cherry red" or "bright orange" really means in degrees. Fornax is that chart, made interactive, for bladesmiths and blacksmiths who read steel by its glow.

PICK YOUR STEEL, SEE ITS HEAT
Choose an alloy and the whole screen fills with the glow color at that steel's representative quench heat, with the temperature called out big. 1084, 5160, 80CrV2, W2, O1, 15N20, 1095 - the workhorses are built in, each carrying a cited working range so you know the number is a starting reference, not gospel.

SCRUB THE WHOLE SCALE
Drag along the heat scale from a dull dark red up to bright white and watch the glow color track the temperature, roughly 500 C to 1,500 C. It answers the question every smith asks the wall chart: "what does 1,500 F actually look like?" - at a glance, in whatever unit you prefer.

THE NON-MAGNETIC MARK
The scale shows the Curie point (about 770 C for plain carbon steel) right where it belongs - the temperature where steel stops sticking to a magnet. It's the field trick you already use; now it's on the scale next to the color.

CELSIUS OR FAHRENHEIT, YOUR CALL
Toggle units and Fornax remembers your choice. It also remembers the last alloy you looked at, so you're back where you left off.

MADE FOR THE SHOP
One screen. No accounts, no sign-up, no tracking, no internet needed. The dark "forge" look keeps glow colors readable in a dim shop. Useful for knife making, general metalworking, and farrier work alike.

A REFERENCE, NOT AN INSTRUMENT - PLEASE READ

Fornax is a training and reference aid, not a measuring instrument and not a safety device. On-screen color varies with your display, its brightness, and the light around you, so it will never exactly match real hot steel. Alloy numbers are common community reference values; alloy chemistry and section size shift the real figures. Always confirm temperatures against your steel supplier's datasheet and heat-treat guidance, judge your actual work with proper tools, and use appropriate eye protection and safety gear at the forge. Never rely on this app as your only gauge.

Made by SmallPaper. Built for the people at the anvil.