Knifemaking

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For more information, see the Knife article.

Knifemaking is the process of manufacturing a cutting instrument by any one or a combination of processes: metal removal (also known as stock removal), forged to shape, Damascus (welded lamination) or cast. Typical metals used come from the carbon steel, tool, or "stainless" steel families. Some of the more exotic or primitive knives may be made from bronze, brass or iron. Other knife materials may include various stones such as obsidian or flint.

Contents 1 Materials for Blades 1.1 Steels 1.1.1 Spring and Plain carbon steels 1.1.2 Tool Steels 1.1.3 Stainless Steels 1.1.4 Powder Metallurgy Steels 1.2 Other Metals and materials 2 Initial Shaping 2.1 Forging 2.2 Blanking 3 Grinding 3.1 Initial grinding 4 Heat Treatment 4.1 Simple Carbon Steels 4.2 Tool Steels 4.3 Stainless Steels 5 Blade Finishes 5.1 Blast Material 6 Handle Materials 6.1 Bone and Horn 6.2 Wood 6.3 Types 6.4 Unfinished 6.5 Finished 6.6 Finishes 6.7 Stabilized 6.7.1 Stabilization Techniques 6.8 Metals 6.8.1 Metal Parts 6.8.1.1 Bolsters 6.8.1.2 Pommel 6.8.2 Cast 6.8.2.1 brass 6.8.2.2 nickel silver 7 Finishing 7.1 Buffing 8 Sheaths 8.1 Materials 8.1.1 Leather 8.1.2 Thermoplastic

[edit] Materials for Blades

Different steels are suited to different applications. It is a tradeoff between hardness, toughness, edge retention, price, and corrosion resistance, achievable sharpness, Also the difficulty of working with the material must be taken into account. Some examples of extremes:

• Obsidian can achieve a nearly molecular edge (high achievable sharpness) and only requires stone age technology to work, but is so brittle that it cannot maintain that sharpness for very long. Also the entire blade is very easy to break by accident.
• The newest powder metallurgy steels can be made very hard, but can quickly wear out abrasives and tooling.

[edit] Steels

[edit] Spring and Plain carbon steels

• 1050
• 1084
• 1085
• 1086
• 1095
• 5160
• 6150
• 52100
• truck springs
• W-1

[edit] Tool Steels

Tool steels suitable for knives include:

• High speed steel
• 15N20
• A-2: Good shock resistance.
• BG-42: Excellent for kitchen knives
• Crucible Metals CPM1V, CPM3V, CPM9V, CPM10V, CPM15V (these should be vacuum heat treated, with cryogenic post treatment)
• D2
• G2
• Hatachi Blue Super Steel (Japanese)
• L-6 Excellent shock resistance. With the proper heat treatment it can be banitic in structure which is extremely tough, but slightly softer than martensite. Swordmaker Howard Clark has a proprietary process however to create a banitic body and martensite edge in his blades. This is analogous to the pearlite/martensite of a traditional Japanese sword.[1], but much stronger.
• M2
• O-1: Oil hardening
• S7
• W-2: Water Hardening

[edit] Stainless Steels

Stainless Steel Cutlery stainless steels are martensitic in nature, and most are variations on 440C.

• 440C was originally developed for jet engine blades.
• 20-CV
• 440A, 440B, 440C, 440F, 440F-Se, 440XH, 440C Cast Dendritic Stainless Steel (first invented and used by David Boye in the 1970s.)

440C Cast Snowflake Steel (2006) Stuart Ackerman in 2006.

• 420HC
• 420J2: Low carbon, resulting in low achievable hardness and poor edge retention, but good corrosion resistance. Used in poor quality knives as it is easy to shear, grind, and heat treat.

• ATS series: ATS34, ATS55 ; Japanese steels.
• 154CM: similar to ATS34
• AUS-4, AUS-6, AUS-8, AUS-10

• GIN-1: Japanese steel
• MBS26: Excellent for cooking knives
• MRS30
• N690
• Sandvik 12C27, 12C27mod; (Swedish steels). Inexpensive to make and machine, good toughness, good corrosion resistance and easy to resharpen.
• T5MOV
• X-15TN
• VG10, another 440C variation, was developed specifically for the knives used in the Japanese grafting industry.

[edit] Powder Metallurgy Steels

To put it simply, "Powder Metallurgy changes the rules."

• CPM154, CPM S60V (formerly CPM440V), CPM S90V (formerly CPM420V), CRUWEAR (From Crucible Metals)

• SV30: was developed by Crucible Metals Corporation specifically for the cutlery market, balancing cost, ease of grinding and machining, and edge retention. CPM S60V had shown promise, but had issues with hardness and chipping.

• ZDP-189: A potentially very hard stainless steel (Hardenable to 67-68 on the Rockwell hardness scale) has less brittleness than usually accompanies such a hard steel. The high hardness and carbide content results in superior edge retention in abrasive situations. Often Laminated with tougher steels.

[edit] Other Metals and materials

• Stellite 6K
• Bronze
• Damascus steel
• Titanium Alloy: nearly pure titanium is far too soft for knife blades, so titanium alloys are used in knives. While having poor edge retention compared to traditonal steels, it is extremely resistant to corrosion, and is nonmagnetic, making it well suited to specialized applications, such as diving or Explosive ordinance disposal.
• Wootz
• Obsidian

[edit] Initial Shaping

[edit] Forging

Forge Anvil Hydraulic Press

[edit] Blanking

In mass production or well equipped shops blanking can be done. This is done with a number of methods, depending on the thickness and the alloy of steel to be cut. Thinner, low alloy blanks can be stamped from sheet. More difficult, or higher production jobs can be done with cnc water jet cutters, lasers or electron beam cutting. These two lend themselves towards larger custom shops.

Knifemakers will sometimes contract out to a shop with the above capabilities to do blanking. For lower production makers, or lower budgets, other methods must suffice. Knifmakers, being resourceful creatures, may use many different methods to profile a blank. These can include hacksaws, files, belt grinders, wheel grinders, oxy-acetylene torches, or any number of other methods depending on budget.

[edit] Grinding

[edit] Initial grinding

If no power equipment is available, this can be done with files if the piece of steel has not yet been hardened. Grinding wheels, or small belt sanders are usually what a beginner uses. Well equipped makers usually use a large industrial belt grinder, or a belt grinder made specifically for knifemaking.

[edit] Heat Treatment

Iron Alloy Phases
Austenite (γ-iron; hard) Bainite Martensite Cementite (iron carbide; Fe3C) Ferrite (α-iron; soft) Pearlite (88% ferrite, 12% cementite)

[edit] Simple Carbon Steels

[edit] Tool Steels

[edit] Stainless Steels

[edit] Blade Finishes

The finish quality of the blade is determined by the Grit of the finishing grind. These can range from a low-shine 150-250 grit finish to a mirror-shine accomplished with a Japanese water-stone, which has an approximate grit of 10,000-12,000. Most high quality manufactured knives have about an 8000 grit finish.

[edit] Blast Material

[edit] Handle Materials

[edit] Bone and Horn

• Cow bone can come in Jigged, Picked or smooth textures. It is often dyed.
• Antlers
• Ivory
• Leather: Can be done in slabs or stacked.
• Mother of Pearl: Very decorative, but brittle. Needs a backing to take structural loads. Varieties include black lip, gold lip, abalone

[edit] Wood

There are several patterns popular in knife handles. These often include more ornate woods like Maple and Cedar. Dymondwood and Pakkawoods are also very popular for custom-made handles.

[edit] Types

[edit] Unfinished

[edit] Finished

[edit] Finishes

[edit] Stabilized

[edit] Stabilization Techniques

[edit] Metals

[edit] Metal Parts

[edit] Bolsters

[edit] Pommel

[edit] Cast

[edit] brass

[edit] nickel silver

[edit] Finishing

[edit] Buffing

[edit] Sheaths

[edit] Materials

[edit] Leather

[edit] Thermoplastic

Kydex and Concealex are the two name brand materials.