Calculator › Knives › Gladius
What size steel for a gladius?
A Pompeii-type gladius, with 19 in of blade 2 in wide and a 7 in hidden tang, comes from 2 1/2 × 1/4 in bar, forged. BladeStock sizes the bar at blade width plus 1/8 in, which is 2 1/8 in, and there is no 1084 width listed between 2 and 2 1/2 in, so 2 1/2 in it is. Pompeii blades usually run about 45 to 50 cm (17.7 to 19.7 in) long and about 5 cm (2 in) wide.
Forged, one blade takes about 12 in of bar: around 34 oz of steel for an estimated 24 oz finished blade. That just misses two to a 24 in bar, so a 48 in bar gives you three, at about $40 of 1084 each at the calculator's starting price. The calculator assumes the blade is drawn out with a distal taper, which is how 12 in of bar becomes 19 in of blade.
Get the tang right. A Roman gladius has a narrow tang that runs all the way through a guard, grip and pommel, usually of wood, and is hammered over at the end to lock them together. That is why the calculator starts this pattern on a 7 in hidden tang. A Pompeii reproduction from Battlemerchant has a hilt about 20 cm (8 in) long with a grip of about 9.5 cm, so measure your guard and pommel before you set the tang length.
Your knife
Advanced: cuts, tong hold & tang
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.
Calibration: fill factors & grinding loss
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, because the bar is cut straight to the profile and 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 (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.
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What this assumed
Steel is only part of the cost. Add abrasives, handle, heat treat and your time, and see the price that actually pays you.
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Three types of gladius
Rome took its sword from Spain. The gladius Hispaniensis is based on the Celtiberian short sword, and at up to about 65 cm it was long for a short sword. That length fits Polybius and Livy, who describe it mainly as a slashing weapon.
Under the Empire the gladius got shorter. Mainz-type blades run about 50 to 55 cm long and 7 cm wide, with a long triangular point, and the best known, the Sword of Tiberius, was found in the Rhine near Mainz and is now in the British Museum. The Pompeii type, named for swords found there, has parallel edges and a short point, and in time it overtook the Mainz type in popularity.
The hilt was never metal. Gladius grips were bone, wood or ivory, and the guards and pommels of Mainz and Pompeii types were mostly boxwood, with some cherrywood. The grip was short and sat tight between a large guard and pommel, so the hand was held firmly in one place. Under the hilt, the tang was a plain narrow bar, and the end was hammered over a washer on top of the pommel to hold everything together.
Stock for a gladius
On thickness, start with 1/4 in bar. On BladeForums, a smith asked whether 3/16 in was right for a gladius; one reply said 3/16 in stock ends up at about 1/8 in, and that he would start with 1/4 in to finish at 3/16 in. Reproductions agree: a Windlass Mainz-Pompeii gladius is listed at 4.7 mm (about 3/16 in) thick.
| Mainz, 20 1/2 in blade, 2 3/4 in wide | 3 × 1/4 in |
|---|---|
| Pompeii, 19 in blade, 2 in wide | 2 1/2 × 1/4 in |
| Hispaniensis, 25 in blade | 2 1/2 × 1/4 in |
Widths assume blade height + 1/8 in rounded up to stock; thickness is the finished spine rounded up. Change the inputs above for your own pattern.
Steels that suit it
Questions
How much steel do I need for a gladius?
For a Pompeii-type gladius with a 19 in blade and a 7 in hidden tang, forged, about 12 in of 2 1/2 × 1/4 in bar: around 34 oz of steel for an estimated 24 oz finished blade. A 48 in bar gives three. A Mainz type, about 20 1/2 in long and 2 3/4 in wide, needs 3 × 1/4 in bar and about 14 in of it.
What steel should a gladius be?
A tough carbon or spring steel. Reproductions are commonly 1065 or 1075 high carbon steel or EN45 spring steel, and smiths forging their own often use 5160. A gladius is long and takes hard knocks, so toughness matters more than edge hardness.
Free: the one-page stock size chart
Bar sizes for ten common knife patterns, weight per inch for the common flat-bar sizes, and quick heat-treat numbers for the usual carbon steels. Print it, tape it to the grinder.