Maker's Glossary

Steel alloyed with chromium (at least 10.5%) which creates a passive oxide layer that resists rust. Easier to maintain than carbon steel but generally harder to sharpen to the same razor edge. Ideal for low-maintenance kitchen use or coastal environments.

A classic high-carbon steel (~0.84% carbon) prized for its reliable heat treatment, ease of sharpening, and toughness. In pattern-welded work it etches to a deep, velvety dark grey/black, which is why we pair it with 15N20 to create the strong contrast in our Damascus billets.

A high-carbon tool steel with roughly 2% nickel content. It performs well as a standalone blade steel thanks to its toughness, but it is best known as the bright, shimmering silver contrast layer in Damascus alongside 1084 — the nickel resists acid etching and stays luminous where the surrounding steel goes dark.

Created by forge-welding multiple layers of different steels together and manipulating them to create flowing, organic surface patterns. Not just beautiful — the layering combines the properties of the different steels, offering a balance of hardness, toughness, and visual drama. Each Damascus piece has a unique, unrepeatable pattern.

Japanese for 'three layers.' A construction where a hard, high-carbon steel core is sandwiched between two layers of softer steel. The hard core provides an exceptional cutting edge while the soft outer layers absorb shock and resist chipping. The transition line (the hamon) is often visible along the bevel as a beautiful watermark.

A Hearth-Fire Forge signature construction. A variation of San-Mai where copper (Cu) is used as one or more of the cladding layers. The result is striking — warm copper visible along the bevels and spine — combined with the performance of a hard steel core. Unmistakable at a glance.

A traditional, advanced Japanese method of forging a blade from a single piece of high-carbon steel with a differential hardening line, rather than laminating a hard core into softer cladding. Extremely difficult to execute well; the resulting blade holds an edge exceptionally long but is more brittle than San-Mai or similar laminated constructions.

A solid, semi-finished length of high-carbon steel — cast or forged into a rectangular, square, or cylindrical block — that serves as the raw starting stock before it is drawn, forged, or ground into a finished blade. In our workshop, billets arrive from small, precision-run batches produced in collaboration with Standen Knives, chosen for their refined grain structure and predictable response to heat treatment. Working from billet (rather than pre-rolled bar or castings) means each blade is shaped from a single, dense piece of steel — stronger, tighter-grained, and free of the internal voids that can hide in poured stock.

The visible line on a differentially heat-treated or San-Mai blade where the hardened edge meets the softer spine or body steel. It appears as a frozen wave along the bevel — both decorative and a mark of authentic craftsmanship.

The standard scale for measuring a steel's hardness after heat treatment. Kitchen knives typically sit between 58–62 HRC. Higher HRC means a harder, longer-lasting edge but a more brittle blade. Lower HRC is tougher and more forgiving but dulls faster. The ideal hardness depends entirely on the knife's intended use.

The process of joining two pieces of steel by heating them to near-melting point and hammering them together under pressure to form a single piece. It is the foundational technique behind pattern-welded (Damascus) steel and requires precise temperature control — too hot and the steel burns; too cool and the weld won't hold.

A concave bevel ground on a wheel — thin, keen edge, excellent for slicing, less robust for chopping.

A rounded knotty growth found on trees, formed when the tree undergoes stress. Burl wood has a highly irregular, swirling grain pattern making each piece visually unique. When stabilised and finished, it produces some of the most striking handles available — no two are ever the same.

Natural wood that has been vacuum-impregnated with resin under pressure, filling all the pores and cells. This makes it far more resistant to moisture, cracking, and warping, while intensifying its natural colour and figure. A lifetime material.

Naturally shed deer or elk antler used as a handle material. Each piece is entirely unique in colour, shape, and texture. Antler is hard, dense, and has a natural rough texture that provides excellent grip even when wet. Traditionally used in hunting and outdoor knives.

Usually sourced from cattle, bone is a traditional handle material used for centuries. It can be left natural, dyed, or jigged (textured) for grip. Bone handles have a smooth, warm feel and develop a subtle patina over years of use.

Buffalo, cow, or stag horn provides a dense, smooth handle material with naturally beautiful colour variations from dark black to warm amber. It has a distinctive translucency when held to light and is slightly flexible compared to bone and antler.

Polymer resin cast around or into handle blanks to create handles with embedded materials — crushed stone, glitter, pigment, wood shavings, or glow-in-the-dark powder. Allows for virtually unlimited colour and effect combinations. Completely waterproof and maintenance-free.

A traditional lightweight, multi-sided (often octagonal or D-shaped) wooden handle fitted to a hidden tang, common on Japanese-style blades. It shifts the balance point forward toward the tip, which suits the push- and pull-cutting motion of Japanese kitchen knives.

A custom-fitted wooden sheath, traditionally shaped from a single block of light timber such as ho wood, that protects a blade's edge from damage and moisture during storage. A properly fitted saya slides on and off with a soft friction rather than sitting loose.

A premium, non-ferrous metal used for bolsters, pins, guard spacers, and pommels. Copper reacts to skin oils and air over time, developing a rich amber-brown antique patina that deepens with use — a living finish, not a flaw.

The collar between the blade and the handle. Adds weight forward, protects the front of the handle, and finishes the transition cleanly.

The two pieces of handle material pinned to either side of a full tang.

A decorative pin built from layered metals — a signature detail on many of our handles.

The angled surface ground into the blade to create the cutting edge. The bevel angle determines sharpness and durability — a lower angle creates a more acute, razor-sharp edge; a higher angle is more robust for heavy tasks. Most kitchen knives are ground between 15–20° per side.

The blade is ground flat from the spine to the edge, creating a triangular cross-section. Produces a very thin, keen edge and excellent cutting performance. Common in chef's and slicing knives.

The blade sides curve outward to the edge (like an 'appleseed') with no defined shoulder. Creates a strong, robust geometry excellent for chopping and splitting. More difficult to sharpen freehand but holds up exceptionally well to hard use — the geometry of choice for field and chopping blades.

A wide, flat single-bevel grind that runs straight from the middle of the blade down to the edge with no secondary micro-bevel. Excellent for woodworking and bushcraft where controlled slicing cuts matter, and easy to maintain freehand on a flat whetstone — you simply lay the whole bevel flat on the stone.

The gradual thinning of the blade from heel to tip along its length. Gives a heavier feel near the handle and a fine, nimble tip. A good distal taper significantly improves balance, reduces wrist fatigue, and is a hallmark of quality craftsmanship.

The curved portion of a blade's cutting edge, engineered to support a rocking cutting motion against a board. It is most pronounced on Western-style chef's knives and much flatter on Japanese-style profiles designed for push-cutting.

The thick, unsharpened top edge of the blade running from heel to tip. Its thickness and taper shape the knife's balance, flex, and how the blade wedges through dense material — a thin spine cuts effortlessly, a thick spine splits.

The steel of the blade extends fully through the handle, matching its full length and width. Handle scales are pinned or fastened to either side. The strongest and most balanced construction, preferred for heavy-use and outdoor knives.

The blade steel extends into the handle as a narrow rod, set into a channel in the handle material. The handle appears as a solid piece with no visible steel on the sides. Creates a very clean, traditional aesthetic common in Japanese-style and chef's knives.

A construction where the blade's tang forms the skeleton (frame) of the handle, with handle material inlaid into the frame. Provides excellent strength and a unique aesthetic where the steel frame is often visible as an accent around the handle material.

A small cutout at the base of the blade near the handle. It allows a sharpening stone to travel the full length of the edge without hitting the handle, and can also serve as a finger notch for a forward 'choked' grip.

The unsharpened section of the blade just above the guard. It provides a safe area to choke up on the blade for fine control, and protects the handle from sharpening wear.

Decorative and structural hardware used to secure handle scales to the tang. Brass and copper pins add warmth; bolsters (metal collars at the blade-handle junction) add strength and a premium finish.

Shaping steel by heating it to a workable temperature (typically orange to yellow heat) and hammering it into shape on an anvil. Forging can refine the grain structure of steel and allows the maker to move and manipulate metal in ways stock removal cannot.

A blade-making method where the shape is cut, ground, and filed from flat bar stock — no forging required. Produces very consistent, predictable results. Often contrasted with forging, though neither is inherently superior.

Slowly heating steel to a specific temperature then allowing it to cool very slowly (often buried in an insulating medium like vermiculite). This softens the steel, relieves internal stress, and makes it easier to grind and drill before hardening.

Heating the blade to critical temperature and allowing it to air cool naturally. Performed multiple times after forging and before hardening to refine grain structure and relieve internal stress. A crucial step toward a predictable, high-quality heat treat.

Heating the blade to its critical temperature (where it becomes non-magnetic) and then rapidly cooling it in oil, water, or air. This locks the steel's crystal structure into a hard — but brittle — state. Without the next step (tempering), the blade would shatter. The most violent and important moment in the build.

After hardening, the blade is reheated to a lower temperature (typically 180–220°C for kitchen knives) then cooled. This reduces brittleness while retaining most of the hardness. The tempering temperature directly controls the final HRC of the finished blade.

The specific temperature at which a steel's molecular structure transforms, allowing hardening to occur. At this point the steel becomes non-magnetic — many smiths test this with a magnet rather than relying on colour alone. Hitting this temperature precisely is the key to a successful heat treat.

The black, flaky iron oxide that forms on the surface of steel when heated in the forge. Must be removed by grinding or wire brushing before finishing. In forge-welded Damascus billets, thorough scale removal between layers is critical to a clean weld.

A rustic, unpolished black forge finish left on the upper portion of the blade after hammering and heat treatment, with only the bevel and edge polished bright. It adds character, hides working marks, and provides a natural, mild barrier against surface rust on the un-ground steel.

Optional sub-zero soak after quenching that pushes more of the steel's microstructure into its hardest form.

The shaped steel block on which a smith hammers and forms hot metal. Ours is a 110kg London-pattern, restored.

The stamped signature on every Hearth-Fire blade — a small hearth flame and the year.

From Old Norse smiðja (feminine noun): a smithy or forge — the workshop of a smiðr, the smith. Cognate with Old English smiþþe, Old High German smitta, and modern Icelandic smiðja, all descended from Proto-Germanic *smiþjǭ. In the Viking Age, the smiðja was both a working structure and a place of standing in the community — where iron was won from bog ore, tools and weapons were forged, and the smiðr held rank alongside poets and shipwrights. We use the word deliberately: our workshop follows the same one-smith, one-fire tradition, scaled for a modern family forge.

A traditional Nordic (particularly Finnish) everyday-carry belt knife with a short, straight spine and no finger guard, letting the hand sit close to the edge for fine carving control. A working tool first — used daily for food, wood, and craft — carried in a leather sheath at the hip.

A large, heavy traditional knife used by the Sámi people of Lapland for demanding bushcraft — chopping brush, processing wood, and butchering. Where the puukko handles fine work, the leuku does the heavy work; the two are often carried together as a pair.

The Japanese equivalent of a Western chef's knife (gyuto literally means 'cow sword'). A flatter profile near the heel supports push-cutting, tapering into a gentle belly near the tip for rocking cuts — a hybrid geometry designed for a Western kitchen but built with Japanese steel and grind sensibilities.