Knifemaking

A knife is a piece of steel that has been given a shape, then given a hardness, then given a handle. The order matters and the middle step is the one that separates a knife from a knife-shaped object: heat treatment is where the performance comes from, and no amount of careful grinding compensates for getting it wrong.

That is worth stating at the top because the craft presents itself the other way round. The images are of forging — hot steel, a hammer, sparks — and forging is genuinely a route in. But the majority of knives made today, including most professionally made ones, are produced by stock removal: the shape is ground out of a flat bar and fire enters only at the heat treatment. Neither route is more legitimate, and stock removal is far easier to start.

The other thing to establish early is what this page is and is not. It is about making. It covers what a blade is, how it is shaped, hardened and finished, and what the law says about a person who makes, owns and might sell one. It says nothing about knives as weapons, nothing about use, and nothing about defence, and that is a boundary rather than an omission.

Two routes in

Stock removal, or forging

Where quality comes from

Heat treatment

The real hazard

The grinder, not the blade

Cheapest real start

Files, vice, sent-out heat treat

Material per knife

£25–£60

1. 1

   Step 1: Do a day course first, if you can

   A one-day introductory course puts you through the whole sequence on somebody else’s equipment and tells you within hours whether you want to own any of it. It is the best value in the craft and it removes the temptation to buy a grinder to find out.

2. 2

   Step 2: Start with stock removal and a simple design

   A flat bar of simple high-carbon steel around 3mm, a straightforward drop-point or a small utility shape, no fancy grind. Complexity at this stage buys nothing except opportunities to be unsure which mistake was which.

3. 3

   Step 3: Profile it with a hacksaw and files

   Cut the outline, then file to the line. This is slow, quiet, cheap and genuinely how a great many knives have always been made. It also teaches you what the steel is doing in a way a grinder does not.

4. 4

   Step 4: File the bevels with a jig, before hardening

   All shaping happens while the steel is soft. A simple filing jig holds a consistent angle and is the difference between a bevel and a mess. Leave the edge about the thickness of a coin — a thin edge will warp or crack in the quench.

5. 5

   Step 5: Send the heat treatment out for the first one

   A commercial service will harden and temper it correctly for a modest fee. This removes the forge, the quench and the most expensive equipment decision from your first knife, and it means that if the blade is good you know the shaping was yours and if it is bad you know it was too.

6. 6

   Step 6: Finish by hand and fit the handle

   Sand progressively through grits to remove the previous scratches rather than to make it shiny — each grit only has to erase the one before. Then handle scales, pins and epoxy, shaped to the tang. Handle shaping is where a knife stops being a blade and starts being yours.

7. 7

   Step 7: Sharpen it last, and expect to be bad at it

   Sharpening is a separate skill from making and a lot of first knives are judged unfairly because of it. It improves quickly with a guided system and it is worth learning on a cheap kitchen knife rather than on the thing you just spent three weekends making.

The sequence of knifemaking is not arbitrary and understanding why each step sits where it does prevents most of the expensive mistakes. What follows is the reasoning rather than a set of numbers — specific temperatures, times and quenchants belong to the particular steel and are published by whoever supplied it.

• Shape while soft, always — Annealed steel files and grinds easily; hardened steel does not, and trying to remove metal after heat treatment is slow, generates heat that ruins the temper, and eats belts. Everything that removes material in quantity happens first.
• Hardening is a phase change, not just heating — The steel is taken above a critical temperature so its internal structure changes, then cooled fast enough that it cannot change back. What comes out is very hard and very brittle. The temperature and the cooling speed are properties of the specific alloy, which is why "what steel is it" is the first question anybody asks about a heat treatment problem.
• Tempering trades hardness for toughness — A comparatively gentle bake after hardening, which relieves stress and makes the blade able to survive being used. It is not optional and it is not a finishing touch — an untempered blade is a hazard rather than a knife.
• A thin edge warps and cracks in the quench — Uneven thickness cools unevenly and the blade moves or splits. Leaving the edge deliberately thick before heat treatment, and grinding it thin afterwards, is the standard answer and the reason the final sharpening happens so late.
• Heat is the enemy after heat treatment — Once a blade is tempered, any grinding that lets it get too hot to hold undoes the tempering locally — usually at the tip and the edge, exactly where it matters. Light passes, frequent dipping in water, and fresh sharp belts. A blue or straw discolouration appearing on the edge is the damage becoming visible after it has happened.
• Finishing is about scratch sequence, not polish — Each abrasive grit exists to remove the scratches of the one before it, working in alternating directions so you can see when the previous set is gone. Skipping grits leaves deep scratches under a shine, which is why a hurried finish looks worse the finer it gets.
• The handle is a fit problem — Scales must sit flat against the tang with no gap, because a gap traps moisture and fails later. Flat surfaces, a clean epoxy line, and pins that are not over-tightened. Most handle failures are surface preparation rather than adhesive.
• Forging changes the route, not the requirements — Forging moves metal to shape rather than removing it, which saves material and allows forms grinding cannot easily reach. It adds its own steps — normalising cycles to refine the grain after all that hammering — and it does not remove the need for a correct hardening and tempering afterwards.

• A solid vice and a bench — The foundation and the thing most often skimped. Filing against a vice that moves is the difference between hard work and impossible work.
• Files and a hacksaw — A decent flat bastard file, a finer one and a hacksaw will make a complete knife. Files are consumable and a worn file is why filing suddenly feels futile.
• A filing jig — Cheap or shop-made, and the single biggest improvement to a hand-made bevel. Consistency of angle is what separates a bevel from a facet.
• A drill press — For handle pin holes through hardened-adjacent steel. Drilling before heat treatment avoids most of the difficulty; a hand drill will do it and will wander.
• A 2x72 belt grinder — The transformative machine and the large expense at £700–£1,500. It replaces days of filing with hours. Budget 2x42 machines and angle-grinder jigs work and are slower and, in the case of jigs, less controllable. This is the purchase to defer until you have finished several knives.
• A gas forge — Needed for forging and useful for heat treating, at £250–£600. Not needed at all if you send heat treatment out, which is the reason to postpone it.
• Heat treatment equipment — A quench tank and the correct quenchant for your steel, plus a way to temper — a kitchen oven is genuinely adequate for the tempering half. Precise temperature control is where the money goes for stainless steels, which is most of why they are sent out.
• Protection, which is not optional — A full face shield, a fitted respirator rather than a paper mask, hearing protection, and extraction at the grinder. This is equipment rather than accessory, and it belongs in the first purchase rather than the fifth.

• Make the same knife five times — The fastest route to competence and the least appealing suggestion in the craft. Repeating one simple design isolates the variables — it becomes obvious which step is inconsistent when everything else is held still.
• Take over your own heat treatment — The step that turns a shaper into a maker. Bring it in-house on simple carbon steel where the schedule is well published and the feedback is quick, and keep sending stainless out.
• Learn to test rather than to assume — A brass rod test for edge stability, a file to check hardness, and cutting until it stops cutting. Makers who test find out what their process actually produces; makers who do not repeat the same error for years.
• Then geometry — Thinner behind the edge, distal taper, and how a grind changes what a knife is good at. This is where knives stop being equivalent and start being designed, and it needs the heat treatment to be reliable first.
• Add forging, if you want it — A separate skill ladder rather than the next rung. Many excellent makers never forge, and the ones who do usually describe it as a different pleasure rather than a better knife.
• Sheaths, marks and the whole object — Leatherwork, a maker’s mark, and finishing to a standard somebody would pay for. This is the point at which people start selling, and it is the point to read the selling rules properly.

• The belt grinder — The single most dangerous thing in a knife workshop. A belt that lets go comes apart at speed and at head height, a workpiece can be snatched and thrown, and small parts pull fingers into the platen. Full face protection rather than glasses, no gloves near the belt, correct guarding, and never standing in the plane the belt would travel if it broke. A grinder is also the place a heat treatment is most often destroyed: friction can take an edge past its tempering temperature without the handle feeling hot.
• The quench — Hot oil and glowing steel together. Oil quenches can and do flash, so a lid within reach, a tank deep enough that the blade is fully submerged, no water anywhere near it, and nothing flammable in the surrounding area. Steam explosions from a wet tank are the failure people do not anticipate.
• Dust and fume — The slow hazard and the one most consistently underrated. Grinding produces fine metal dust, and shaping handle scales produces wood dust — which the HSE states can cause asthma, and which in the case of hardwoods can cause cancer, particularly of the nose. Those are the regulator’s findings about a workplace regime that creates no legal duty in a home workshop, and the health effects do not care which it is. Extraction at the source, a fitted respirator rather than a paper mask, and wet processes where they are available are the mitigations. The HSE is the authority here rather than knifemaking forums.
• Hardened steel is brittle — A blade between hardening and tempering can shatter if it is dropped or flexed, and shards travel. This is a short window and a real one, and it is a reason to temper promptly rather than leaving a hardened blade on the bench overnight.
• Fire and carbon monoxide — A gas forge is an open flame producing a great deal of heat and combustion products. It needs ventilation that actually moves air rather than an open door, separation from anything that burns, and it is not a garage-with-the-door-shut activity. Follow the manufacturer’s instructions for the specific forge, which are the authority on its clearances.
• Noise and vibration — Grinders, forges and hammering are sustained loud, and hand-arm vibration from long grinding sessions is a genuine occupational risk rather than a theoretical one. Hearing protection every time, and breaking up grinding rather than doing it in one long stretch.
• Sharpening and handling — Worth stating even though it is not the main event: a knife is at its most dangerous when it is nearly finished, because it is sharp and does not yet have a handle. Cut away from yourself, and put a finished blade down rather than carrying it in a hand doing something else.

This is the section most often got wrong online, usually because a maker’s question and a carrier’s question get answered together. They are different, and the maker’s question is the narrower one.

Making a knife for yourself is not a regulated activity. There is no licence, no registration and no restriction on owning what you have made, and the law that people argue about is about carrying in public and about selling.

• Carrying in public — It is an offence to have an article with a blade or sharp point with you in a public place without good reason or lawful authority. The exemption for a folding pocketknife requires the cutting edge to be no longer than three inches — and the knife must not lock. A locking folder falls outside the exemption whatever its size, which is the detail most commonly misstated. Good reason is decided on the facts; use for work, religious observance and national dress are named.
• Taking your own knife somewhere — Making it does not create an exemption. Transporting a knife to a show, a course or a customer is a carrying question like any other, and the sensible practice is that it is boxed, wrapped and not accessible — the same way a tool is transported rather than the way a knife is carried.
• Selling — There are restrictions on selling knives to people under 18, and some types cannot lawfully be sold at all. If you intend to sell what you make, that is the point to read the current legislation and guidance rather than a summary, because the prohibited list is amended and this page deliberately does not reproduce it.
• Prohibited types — Certain knives are banned from sale, hire, import and possession by their mechanism or type rather than by their size. This page names none of them individually, because the list changes and a stale list read as current is worse than no list. The Government guidance is the place to check before making something unusual.
• What this page does not cover — Nothing here is about knives as weapons, about self-defence, or about what a knife is for. This is a making page and that boundary is deliberate. It is also not legal advice: it points at the statute and the guidance, and where a decision matters those are what to read.

• Stock removal — Grinding the knife out of flat bar. The mainstream method, the easiest to start, the one that needs no forge, and how most professionally made knives are produced. Nothing about it is a compromise.
• Forging — Moving hot steel to shape with a hammer. Slower to learn, more equipment, and it opens forms and material efficiencies grinding cannot reach — plus it is the reason many people are here at all.
• Hand-filed knives — No powered shaping at all. A real tradition rather than a beginner’s compromise, it needs a vice and files and nothing else, and it is the only route that works in a flat with a shared wall.
• Kitchen knives — The most useful thing to make and the most demanding geometry: thin, hard, precise, and judged every day by somebody cooking. A different design discipline from an outdoor knife.
• Outdoor and bushcraft knives — Thicker stock, tougher heat treatment, simple robust handles. The most forgiving category to start in because the geometry is less critical.
• Pattern-welded steel — Forge-welding layers of different steels to produce a visible pattern. Advanced, spectacular, and a specialism within forging rather than a step along it.
• Handle making and sheaths — A craft of its own that many makers end up preferring. Leather sheath work in particular is a separate skill set with its own tools, and a poor sheath undoes a good knife.
• Restoration and sharpening — Bringing old blades back and learning to put a genuinely good edge on. The cheapest way to learn steel behaviour and finishing, and it requires none of the heat-treatment equipment.