What size steel for a seax?

The seax is a forging knife: the broken-back profile comes naturally from forging a point down on a straight bar, and the long hidden tang is drawn from the same billet. 1 1/2 × 3/16 in bar makes a 7 in blade with a full flat grind. Historic large seaxes were often thicker than modern reproductions (the Seax of Beagnoth is over 5/16 in at the spine with no distal taper), so 1/4 in is period-correct for a big broken-back; small utility seaxes were thin.

Because there is no ricasso to speak of and the edge is straight, the bar width is set by the tallest point of the blade just before the break, and the calculator's height input should be that dimension.

What a seax was — and what the word actually means

Start with the correction that matters: seax is simply the Old English word for knife. The language compounds it for every kind of blade: a lancet (blód-seax), a razor (scear-seax), a pruning knife (wíngeard-seax), a scribe's knife (writ-seax), a meat knife (mete-seax). So calling something "a seax" says roughly as much as calling it "a knife." The big single-edged blade people mean by the word is one end of a very wide range, and the small utility knife is the norm. Härke found iron knives in 45–50% of fifth- to seventh-century English burials, in men's, women's and children's graves alike; at Coppergate in York, 63% of seventy-nine unbroken knives measure 80–120 mm in overall length, with blades alone clustering nearer 50–80 mm. These were tools, and some of them were also weapons.

The broken-back profile (a level or slightly rising spine breaking at a sharp angle down to the point) is a late and largely English variant, common in the 8th to 10th centuries and about 19% of the Anglo-Scandinavian knives from Coppergate. Curved-back is the commoner shape across the whole period. On the larger seaxes the tang runs down the centreline of the blade rather than along the spine, seated in a one-piece wood, horn or bone hilt with no guard and no pommel; paired sheath fittings and carved stones such as Niederdollendorf and Repton point to a two-point suspension with the knife worn more or less horizontally, edge upward. None of that is established for the small utility knives, which are most of the class.

Two more things worth knowing before you sell one as historical. The size typology (narrow seax, broad seax, langseax) is 19th and 20th-century archaeologists' labelling rather than period usage, though hand-seax, mete-seax and wæl-seax are all genuine Old English; and "scramasax" comes from a single occurrence in Gregory of Tours' sixth-century Historia Francorum and is not attested in Old English at all. The Seax of Beagnoth in the British Museum, the famous one with the runic alphabet down the blade, is a spectacular outlier at 721 mm overall and 985 g, not a typical example. Its runes are genuinely botched (four out of sequence, one squeezed in as an afterthought), which suggests whoever cut them was not used to working in runes and may have been copying from a manuscript. Whether Beagnoth was the smith, the rune-cutter, the owner or a giver is unresolved; R. I. Page's conclusion is that we cannot know.

Stock for a seax

Seaxes forge from about 5 in of bar into a 12 in knife, a 2.6:1 draw, and about as far as a hidden tang stretches by hand. A press or a power hammer makes the same job comfortable rather than heroic.

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