Using Our Billets

Firstly, thanks for using our steel! We really appreciate the support and hope you enjoy using our billets. Please tag us in your social media posts — we always love seeing what you create.

Here are some techniques and order of operations to get good results. We assume everyone using these billets has made at least a couple of knives before, so this guide focuses on working with san-mai and pattern-welded steel, along with some extra tips for the best results.

Straightening and Descaling

Straightening is important, as you can't grind san-mai straight or the pattern will be uneven. Don't let this put you off, though — these billets are easy to work with.

Our billets come annealed and ready for grinding. They are usually pretty straight, but some may need a slight adjustment. Straightening can be done during heat treatment while the blade is hot, or by hammering over a soft surface while the steel is annealed. Keep this to a minimum to avoid inducing stress in the steel.

We find the best surface finish on forged billets is with the scale removed but the forge texture untouched. Most of the scale is very thin and will fall off our billets easily; the rest can be picked off with a scraper. Wrought iron or Damascus-clad billets can cling to the scale a little more and may require a needle descaler, or soaking in vinegar overnight followed by wire wheeling. Descaling before heat treat can help prevent warps and leave you with a nice, even, and durable finish.

Post-heat treat straightening can be done using a number of methods — stick to what you know. We like to heat treat with a partial quench and finish between aluminium plates to keep things straight, but further adjustments can be made if necessary. One method is to bend it a little past straight and heat carefully until you feel the tension release (without going past a straw colour near the cutting edge). Cooling with water on one side can also add or remove a little bend. A carbide hammer to peen one side works very well too. Do not grind a bent san-mai blade straight.

Heat Treat

We offer a heat treat service. We cannot guarantee billets that have been heat treated by other companies, so please check them thoroughly before sending them off and ensure you trust the provider.

Centreline cracks (usually found with dissimilar laminates like stainless and wrought iron) are caused by improper preparation for heat treatment and will not be covered by our guarantee, though we are always happy to advise and troubleshoot. If we do the heat treat, a straight (within reason) and crack-free blade is guaranteed, and any potential problem areas will be discussed beforehand. View our heat treat information here.

Bevelling

We recommend grinding all your bevels post-heat treat. This makes straightening easier and ensures your bevels are decarb-free, which is vital for a smooth, dark etch. Using an old 80-grit belt to grind in 45–60 degree bevels before moving to a fresh 36-grit will increase the life of your coarse belts and give rough guidelines for centring the edge.

The exact centre can be found by grinding symmetrically using the nickel lines as a guide. Go slow, frequently check your edge thickness, and look down the blade to ensure it stays straight. Occasionally the blade may bend as you grind (more common in billets with softer outer claddings like wrought iron or stainless steel) — switching sides often helps. Be careful not to remove too much material from areas that may have warped towards the belt.

We like to grind to 3/4 bevel height to where the nickel is just visible along the whole blade on both sides, then neaten everything up with an 80-grit belt. Grinding vertically or with a waterfall platen helps achieve the most consistent edge, pattern, and plunge lines. For kitchen knives, grind the edge down to around 0.2–0.4mm (depending on desired durability), then convex to sharp.

Finishing

There are many ways to finish these billets, so stick to what works for you. Taking it to 320-grit on the belt sander gives a good level of flatness for hand sanding. If done well, you can start hand sanding at 1000-grit, though you'll most likely need to work up the grits (e.g., 320/400 up to 1000) to properly smooth the surface. Rhinowet paper is excellent for this; if using stones, avoid cheap silicon carbide paper.

Cleaning and degreasing is a crucial step before etching. Warm water and dish soap work well. Check after a very short etch to make sure you didn't miss any areas. Every carbon steel blade needs protection — we highly recommend a carnauba wax-based product (like our Leather and Knife Balm) as it lasts longer than oil and doesn't leave streaky marks.

Specific Finishes

Dark-Mai

While we can't give away the details for our 'special black' finish, you can get close with repeated polishing and etching with coffee. Most of our etching is done in ferric chloride.

We love the look of etching in ferric and then buffing off the oxides to a smooth satin grey colour, which contrasts the polished nickel line nicely. For a dark black finish, try a few repeats of etching and cleaning off with fine wire wool. When it comes out of the ferric for the third time, neutralise and dry with compressed air without touching it. This lets the oxides 'set' and become more durable. Add a bit of WD-40 and let it sit overnight, or apply our KWB Iron-Guard coating for maximum protection and non stick.

Stainless Clad

Stainless san-mai can be finished in the same way as dark san-mai. Finer surface finishes and polishing post-etch may decrease the carbon migration colours. This can be a desirable effect, or you can bring the colours back with another etch.

We recommend a couple of etching and polishing cycles followed by an orange juice etch. Clean off and oil without touching, or apply our KWB Iron-Guard coating for maximum protection and non stick..

Damascus

The process is similar to our Dark-Mai finish, but requires 2000-grit paper to sand the highlights after the first etch. Repeat the etching and polishing process using fine wire wool, ultra-fine Scotch-Brite, or a buffing wheel until you achieve the desired contrast.

This can then be finished with an overnight coffee etch and lightly cleaned up with a jewellery polishing cloth before oiling. Alternatively, you can apply our KWB Iron-Guard coating for maximum protection and a non-stick surface.

If you have any issues or questions during the process, please feel free to reach out. We are always happy to advise and help troubleshoot to ensure you get the best results.