We use US-made virgin 1075 for our knives. 1075 is a simple high-carbon steel with a long history of use as a spring steel, and a long standing reputation for toughness. We rely on 1075 to provide the right blend of performance, quality and value.
We use US-made virgin 6150 for our knives. 6150 is a medium-carbon alloy steel - similar to 5160 - with enhanced toughness, impact strength, and abrasion resistance. 6150 is perfectly suited to provide the ideal properties for professional-grade throwing knives. 6150 is essentially 1050 steel with additional chromium and vanadium.
We use German-made virgin 8670 for our knives. 8670 is a high-carbon tool steel that is commonly used to manufacture large metal-cutting circular saw blades. Its composition provides the framework for a tool with excellent resilience and toughness. 8670 is essentially 1070 steel with additional chromium and nickel.
We use German-made virgin 80CrV2 for our knives. 80CrV2 is also a high-carbon tool steel that is ideal for tough knives. 80CrV2 is essentially 1075 or 1080 steel with additional chromium, nickel, and vanadium.
We use US-made virgin O1 steel for our spikes. O1 is a classic and ubiquitous high-carbon tool steel that has a long-standing reputation for quality and consistency. Our decision to use O1 is largely based on availability and workability.
Our standard tumbled finish is not a coating. It is a low-luster polish with exposed steel. Care must be taken to minimize corrosion.
* Balance ratio is measured from the tail end
Steel composition and quality determine only the potential for desirable performance. The heat treatment brings this potential to life. Just as the firing process transforms raw clay into ceramic, the hardening process transforms soft annealed steel into a tough and resilient tool.
We are proud to employ the expertise of Peter's Heat Treating for our production batches. Smaller batches are hardened in our shop, using proven methods and equipment. All batches are tested for quality.
How our knives are made
We use a combination of high-tech automated processes and low-tech handwork to build our knives. All labor is performed in the USA.
Generally each design starts as a pencil sketch or paperboard cutout. Once the initial concept is established, the design is traced into a computer drawing program and converted into a CAD file. At this stage, overall weight and balance are calculated, while ergonomics and performance are thoroughly considered. The shape is exhaustively adjusted until a final draft settled upon. We build prototypes to test each prospective design, and make further adjustments until the design is finalized.
- Shape cutting
We outsource the shape cutting to a metal fabrication shop. The CAD files are used to program a computer-controlled (CNC) laser or waterjet machine. We supply the tool-steel plates, and the shop accurately cuts our knife patterns.
- Prep grinding and machining
In our shop, we perform some preparatory grinding and machining on the shapes, one at a time. The grinding is done manually on a 2x72 inch belt grinder. Lanyard holes are drilled and chamfered on a drill press.
- Heat treatment
We outsource the heat treatment to a shop that specializes in cutlery. The shop processes our knives in accordance with our requirements, and tests each batch to confirm that target specifications have been met. Occasionally the knives are heat-treated and tested in our shop.
After heat treatment, we tumble the knives in our shop. The knives are placed in a rotating drum along with abrasive ceramic polishing stones and a cleansing solution. The tumbling process cleans and polishes the steel, and smooths any sharp corners or edges.
- Final bevel grinding
In our shop, we perform the final bevel grinding on a 2x72 belt grinder. Each knife is ground by hand, one at a time.
- Logo marking
In our shop, we mark each knife with the Flying Steel logo, using an electro-etching machine with custom stencils.
- Final inspection and cleaning
We carefully inspect and clean each knife. Finally, we apply a food-grade oil to deter corrosion.
Steel is truly an amazing material. It can exhibit a vast range of physical properties such as strength, toughness, resilience, abrasion resistance, ductility, and brittleness. The chemical composition of steel determines the potential for desirable properties - the heat treatment brings this potential to full realization.
By definition, steel is composed of iron, carbon, and various other elements such as manganese, chromium, nickel, vanadium, and molybdenum.
Of all the alloying elements, none plays a bigger role in the properties of steel than carbon. The carbon level determines if and how the steel will respond to heat-treatment. Because of this, steel can be usefully categorized by carbon content.
At 0% carbon, pure iron is ductile, but lacks most of the other aforementioned properties. At 2% carbon, 'cast iron' is brittle, but lacks most of the other properties. In the carbon range of 0.1% to 1.2%, desirable properties such as strength, toughness, resilience, hardness, and abrasion resistance can be achieved. Lower carbon levels are generally equated with strength. Medium carbon levels are generally equated with toughness, resilience, and strength. High carbon levels are generally equated with hardness and abrasion resistance. However, these trends can be heavily manipulated through heat treating techniques or the presence of other alloying elements.