Forging temperature table by steel grade
Quick answer
Most carbon and tool steels forge between about 1,500°F and 2,100°F, glowing bright orange to yellow, while mild steel takes a wider range up to roughly 2,300°F. The table below lists each common steel's working range in °F and °C, the glow colour to look for, and the temperature where it starts to burn.
Steel does not come with a thermometer - it tells you its temperature by how it glows. This reference table pulls together the practical forging ranges for the steels beginners use most, so you can match the colour in your forge to a real number. Judge the glow in dim light: bright shop lighting makes hot steel look cooler than it is, which is how beginners overheat and ruin good stock.
| Steel | Forging range | Approx. °C | Glow colour | Do not exceed | Common use |
|---|---|---|---|---|---|
| Mild steel (A36) | 1,600–2,300°F | 870–1,260°C | Orange to light yellow | 2,400°F | Practice stock, hooks, tongs, brackets, general fabrication |
| 1084 | 1,500–2,100°F | 820–1,150°C | Bright orange to yellow | 2,200°F | Simple high-carbon knife steel - forgiving heat range for beginners |
| 1075 | 1,500–2,100°F | 820–1,150°C | Bright orange | 2,200°F | Tough knife and tomahawk steel |
| 1095 | 1,450–2,050°F | 790–1,120°C | Orange | 2,150°F | High-carbon knife steel - narrower safe range, watch for sparks |
| 5160 | 1,500–2,150°F | 820–1,180°C | Orange to yellow | 2,250°F | Spring steel for swords, large knives, leaf-spring stock |
| W2 | 1,500–2,050°F | 820–1,120°C | Orange | 2,150°F | Water-hardening tool steel; fine knives and hamon work |
| 15N20 | 1,500–2,100°F | 820–1,150°C | Bright orange to yellow | 2,200°F | Bright nickel layers for pattern welding; pairs with 1084 |
| 4140 | 1,600–2,200°F | 870–1,200°C | Orange to yellow | 2,300°F | Hammers, hardy tools, axles and shafts |
| O1 | 1,550–1,900°F | 840–1,040°C | Dark orange to orange | 2,000°F | Oil-hardening tool steel with a tight forging window |
How to read the table
Work from the top of the range downward. Bring the steel up to its high colour, forge until it drops past the low end, then reheat - do not keep hammering cold metal, and never push past the overheat column, where carbon burns out and the steel sparks and crumbles.
The °C column is rounded to the nearest 10 degrees for quick reference. Simple steels like 1084 and mild steel are forgiving and ideal for learning; tight-window grades like O1 punish overheating, so save them for when your colour-reading is dialled in.
Want just one steel at a time, with a glow band drawn on the colour ribbon? Use the forging temperature chart tool.
Frequently asked questions
What temperature do you forge steel at?
Most carbon and tool steels forge in a roughly 1,500-2,100°F window, glowing bright orange to yellow. Mild steel tolerates a wider range up to about 2,300°F. Always stay below the grade's overheat point, listed in the table above, because past it the steel burns and is ruined. Work down from the top of the range and reheat rather than forcing cold metal.
What colour is steel at forging temperature?
At forging heat, carbon steel glows from a dull-to-bright orange at the low end up to yellow near the top of its range. Mild steel can reach a light, near-white yellow before it burns. Read the colour in dim light, because bright light washes out the glow and makes the steel look cooler - and therefore hotter than you think it is - which leads to overheating.
How do I know if I have overheated the steel?
Overheated steel throws bright sparks as its carbon burns, looks wet or shiny at the surface, and may crumble or crack under the hammer. If you see sparks coming off the piece while it sits in the forge, it is too hot: pull it, let it cool, and turn the forge down. Once steel has badly burned it cannot be saved and should be cut off.
Do different steels really forge at different temperatures?
Yes. Simple high-carbon steels like 1084 and 1075 have wide, forgiving ranges, while grades like O1 and 1095 have tighter windows and burn more easily. Mild steel forges hotter and more forgivingly than most. Matching your heat to the specific grade - not a single generic number - is what keeps the steel sound and workable, especially for knives.
Last verified 2026-06. Specs, sizes and market prices change - confirm details on the retailer page before buying.