Hobbies are rewarding. They offer a great way to spend a lazy afternoon while exercising creativity. Forging a knife may be a risky hobby, but the results are very satisfying.
Forging knives fall under the broad art of bladesmithing, the art of cutting and shaping blades using forges. It dates way back when humans made blades from rocks, bones, and flints. Later, more robust materials like copper and iron replaced the brittle stones and bones. And the search for solid materials to forge blades continued up to today, where steel rules.
Professional bladesmithing requires skills in metalworking, woodworking, and leatherworking. Sounds like a lot of work? Yeah! But not that much. The process below shows you everything you need to know to forge a knife at home.
Thousands of knife brands exist in the market but forging one has some advantages. To start, with the needed tools, the process is cheaper than buying a ready-made knife. The cost goes down to your time only.
Additionally, customization can get as far as you want. Your room for creativity is vast, and the blade gets a story in the process. Usually, getting a manufacturer custom-make a knife to your taste is very costly. Convinced you want to add a custom blade to your cutlery set? Let’s dig deeper.
Take a look at: How To Sharpen A Knife With A Whetstone
It would be best if you had the following tools:
- Protective wear(gloves, goggles, and an apron)
- Tongs or big pliers
- Chisels, Punches, and Drifts
- Fuel for forge
- Quenching Oil and Metal Storage Container
Choose your metal
Modern-day bladesmithing uses steel. The hardness, strength, and edge retention ability sets steel apart from other metal options. There are two options to acquiring quality steel for your blade:
- Buying a steel bar: For preciseness and better quality forges, there are steel bars you can order from manufacturers. Of course, a shaped bar is easier to work with but comes at a cost. And you are sure of the steel type and the resulting blade characteristics.
- Re-use scrap or junkyard steel pieces: If you are the thrifty type, venture into a junkyard. They are all viable raw materials from railroad spikes, coil, and leaf springs to car suspension springs. They are made with wear-resistant steel that needs more annealing work, but you’re sure to get a good blade out of them.
Types of steel
The steel options you got are carbon, tool, and stainless steel types. Each has pros and cons and varying degrees of handling difficulty.
Carbon steel has excellent strength and hardness due to its high carbon content. The resultant blades have good impact endurance but lose an edge fast. The most popular carbon steel for forging knives is the C1045, but the options are numerous.
Tool steel produces excellent all-season blades. This steel has added alloys that make it robust, corrosion-resistant, and retain an edge for long. However, there is a property trade-off for different types of tool steel. For instance, A2 trade-offs rust resistance to toughness, and D2 retains an edge well but is not tough enough for high-impact works.
Stainless steel is the favorite steel type for kitchen appliances and silverware. And can also be used for forging blades. The Chromium and other alloys improve the stainless steel’s corrosion resistance, though not as tough and edge-retaining as tool steel. Some types like 440 can make a pretty good blade.
Choose your fuel
Once you have settled on your forging steel, it’s time to decide on fuel for the forge. Most fuel types are ideal, but their favourability largely depends on your forge setup, availability, and sourcing location. Popular forge fuels:
- Propane: This fuel gives a clean and incredibly hot flame, and is readily available too. You can get a forge with an integrated propane burner or exercise your DIY skills by making a propane torch.
- Coal: Many forges fit coal easily, and this fuel burns to very high temperatures. It would be best to have good ventilation in your workshop as coal can smoke you out quickly. The resulting smoke is thick and may get you heavily fined by local authorities. Check if local laws allow the use of coal at home and ventilate your workshop well.
- Charcoal: A very affordable and readily available fuel, but not efficient with forging. Maintaining high temperatures with charcoal is not easy, but it’s worth a try if it’s your only option.
You have chosen your steel and forging fuel and all the other tools ready for the work ahead. Let’s forge that blade:
- Put on your protective gear and fire up the forge.
- If there is a thermostat included with the forge, set temperatures to 2,200 degrees Fahrenheit, but if not, use a hot steel color guide. Place the forging steel in the hottest place of the forge.
- When your steel gets a straw or yellow color, use the tongs to place it on the anvil for hammering.
- Hammer one side of the steel bar to form an edge while leaving a space (5.1 cm) for the tang. Flip the blade over for even hammering, unless you want to warp one side of the blade.
- Hammer out flat edges to make angles, the blade bends back on the spine while working on the bevels, fret not; it is normal.
- Hammer out any mushrooming and bendings over the spine.
- Once you got a basic knife shape, it’s ready for annealing; heating to a red color (3000 F), and air-cooling the blade.
- Annealing 2-3 times softens the metal for easier shaping. For a softer and easy-to-file edge, let it cool overnight after the third heating.
- After annealing, sand your blade or file it to give it a polished look before we get to quenching.
- Quenching involves heating the blade to red color and quickly cooling in water or oil; the process locks the molecules within the steel together. Submerge into the coolant tip-first, and stir the blade for fast and even cooling. Quenching hardens the blade.
- At this point, the blade is hard but very brittle. Brittleness requires some softening through tampering. The process involves oven-heating the knife for 2 hours at 3000F, then water-cooling. There you have a dagger ready for the finishing touches.
- Finishing touches: involves drilling holes on the tang for screwing the handle and then sharpening your knife with a fine file or a whetstone. Finally, use a leather strop with polishing paste to remove the burr.
Precautions and protection gear
Forging a knife involves spark-producing processes, so make sure you protect your eyes. Be careful with cut metal as it’s usually sharp and hot. Don’t be careless even with flat edges, as they have burrs. No one needs deep cuts and burns.
Must-have safety gear includes:
- Safety goggles
- Form earplugs
- Disposable mask or respirator
- Leather gloves or welding gloves
- Cotton clothes
- Fire extinguisher
Forging a knife process is as dangerous as it’s intriguing. Get yourself a set of protective wear before getting that steel hot. Don’t worry if your first forge looks ill and takes longer to do. More practice is what you need for awesome forges in the future.
Knife forging is a fun way to pass time while making special collections. And the blades you can forge are limitless, from daggers to outdoor knives. Happy forging!