Calculator › Steels › O1
O1 is the machinist's tool steel and a steel plenty of bladesmiths forge: it is sold precision ground and flat in every size, it holds an edge well, and it heat treats reliably in a kiln with a modest soak. In the forge it moves stiffer than 1084 and has a narrow window, and it still needs the soak at hardening to dissolve its carbides.
| Good for | Forged and stock-removal hunters, EDC and kitchen knives, woodworking tools; makers with a kiln, or a forge they can hold at an even heat. |
|---|---|
| Forging | 1800–1950 °F, do not forge below 1550 °F — a narrow window, and it moves stiffer than 1084 |
| Normalize | Buy annealed. After forging, normalize once at 1600–1650 °F, then anneal 1425–1450 °F with a slow cool |
| Austenitize | 1475–1500 °F, 10–30 min soak (mills say 30 min per inch) |
| Quench | Medium oil (Parks AAA); high hardenability |
| Temper | 400 °F twice → 60–63 HRC |
| Working hardness | 60–63 HRC |
Typical shop values. Confirm against your supplier's datasheet.
Precision-ground flat stock in every thickness from 1/16 to 3/8 in and widths from 1 to 4 in at knife suppliers (industrial suppliers go to 1 in thick and 12 in wide), in 12, 18, 24 and 36 in lengths. The widest range of any steel here.
Suppliers: New Jersey Steel Baron Alpha Knife Supply Jantz
Stock removal: the bar is cut to blade + tang + clean-up, so the tang section and forged thickness below only change the finished-weight estimate. Switch to Forged and they change the stock length too.
Tang dimensions are estimated from the tang style until you change them. Measuring yours is worth doing — a forged blank's length depends on the tang's cross-section, not on what the tang is called.
Stock removal: fill factors only change the finished-weight estimate here. They set the stock length when the method is Forged. Grinding loss has no effect at all in stock removal — the bar is cut straight to the profile, nothing is drawn out.
The fraction of the blade's and tang's bounding box that is actually steel once the bevels are ground. Distal taper is factored in separately now (see "Distal taper" below, under What this assumed) and isn't editable here yet — these two fill factors are the ones worth replacing with your own measurements: weigh a finished blade, then adjust until the finished weight below matches the scale.
Steel is only part of the cost. Add abrasives, handle, heat treat and your time, and see the price that actually pays you.
Copy link to this calculationYes, plenty of smiths forge it. Keep it in its window (1800–1950 °F, nothing below 1550 °F): it moves stiffer than 1084 and cracks if it's hammered cold. Then normalize, anneal, and give it the full soak at hardening, or it comes out soft.
Bar sizes for ten common knife patterns, weight per inch for every standard flat bar, and quick heat-treat numbers for the usual carbon steels. Print it, tape it to the grinder.