BG-42 Powder steel from the USA
BG-42 high-performance stainless steel from the USA
Clean vacuum-produced steel originally developed for demanding aerospace components and highly loaded bearings. In knife making, it offers good edge retention, wear resistance and practical corrosion resistance.
BG-42 is an American high-performance martensitic stainless steel originally designed for critical aerospace components and highly loaded precision bearings. Thanks to its cleanliness, hardness, wear resistance and ability to retain an edge, it later also found its way into premium knife production.
Unlike SG2, ZDP-189, CPM S35VN or Böhler M390 Microclean, the original BG-42 is not produced by powder metallurgy. Traditional BG-42 is manufactured using a double-vacuum VIM–VAR process – vacuum induction melting followed by vacuum arc remelting.
This manufacturing method helps achieve high cleanliness and reduce undesirable inclusions, which was particularly important for its original aerospace and bearing applications. In a kitchen knife, properly processed BG-42 offers stable edge performance, good wear resistance and reliable cutting performance.
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What does VIM–VAR production mean?
VIM stands for vacuum induction melting and VAR for vacuum arc remelting. During production, the steel therefore passes through two technological steps under vacuum that help control its composition and increase the cleanliness of the resulting material.
1. Vacuum induction melting
During the VIM process, the raw materials are melted in an induction furnace under reduced pressure. The manufacturer can control the composition of the melt more precisely and reduce undesirable gases and impurities.
2. Vacuum arc remelting
During the VAR process, the prepared material is remelted using an electric arc under vacuum. This further improves the cleanliness and homogeneity of the steel.
BG-42 is not a conventional powder steel
Powder metallurgy and double-vacuum melting are two different technologies. According to the material specification, original BG-42 is produced using the VIM–VAR process, not by atomising molten steel into metal powder. Both technologies can produce very high-quality materials, but their names should not be confused.
BG-42 steel composition
BG-42 contains a relatively high proportion of carbon together with chromium, molybdenum and vanadium. These elements form carbides that contribute to wear resistance and edge retention. Chromium and molybdenum also support the material's corrosion resistance.
| Element | Typical content | Main role in the steel |
|---|---|---|
| Carbon | 1.15% | Supports hardness, carbide formation and edge retention. |
| Chromium | 14.50% | Contributes to corrosion resistance and carbide formation. |
| Molybdenum | 4.00% | Supports wear resistance, hardenability and corrosion resistance. |
| Vanadium | 1.20% | Forms hard carbides and contributes to edge durability. |
| Manganese | 0.50% | Assists in steel production and heat treatment. |
| Silicon | 0.30% | Used, among other things, as a deoxidising element during production. |
The values shown represent the typical composition of original BG-42 steel according to the LESCALLOY BG42 VIM–VAR material data sheet. The actual analysis of a specific melt may vary within the limits of the relevant material specification.
What does BG-42 bring to a kitchen knife?
Good edge retention
The high proportion of carbon and carbide-forming elements helps the edge resist wear during regular cutting.
Wear resistance
Chromium, molybdenum and vanadium carbides contribute to the material's resistance to abrasive wear.
Corrosion resistance
BG-42 is a stainless steel with good corrosion resistance. Nevertheless, it still requires normal care, hand washing and immediate drying.
High cleanliness
Double-vacuum melting helps reduce undesirable inclusions and creates a material intended for demanding applications.
BG-42 hardness and heat treatment
The BG-42 material data sheet lists different final hardness values depending on the selected hardening and tempering regime. In knives, values of approximately 59–62 HRC may be encountered, but the exact hardness of a specific blade must always be stated by its manufacturer.
Higher hardness can help extend edge retention, but by itself it does not mean that the knife will cut better. The final properties are also influenced by the quality of the heat treatment, blade geometry, thickness behind the edge and the method of final sharpening.
Heat treatment of BG-42 may also include a cryogenic or sub-zero stage that helps transform some of the retained austenite. However, the specific procedure may vary between manufacturers.
The steel designation is not the whole story
Two knives made from BG-42 may offer different cutting performance. The difference comes from heat treatment, blade construction, grind, material thickness and final sharpening. When choosing, therefore, consider the entire knife, not only the name of the steel used.
BG-42 versus modern powder steels
| Property | BG-42 | Powder steels |
|---|---|---|
| Production method | Double-vacuum VIM–VAR melting. | Atomisation of the melt into powder followed by consolidation. |
| Microstructure | Highly clean conventionally produced steel. | Generally finer and more evenly distributed carbides. |
| Edge retention | Good to high depending on processing and geometry. | Varies greatly depending on the specific alloy. |
| Corrosion resistance | Good with proper care. | Depends on the composition of the specific powder steel. |
If you want to compare BG-42 with modern materials produced by true powder metallurgy, also explore the category of premium powder steels .
Sharpening BG-42 knives
BG-42 offers good wear resistance, so sharpening may require a quality sharpening stone and precise technique. For normal edge restoration, you can begin with a medium grit and then continue with a finer stone depending on the desired level of finishing.
When sharpening, maintain a stable angle and work evenly along the entire length of the edge. Suitable equipment can be found in the category knife sharpening and sharpening stones .
Proper care of a BG-42 knife
- Wash the knife by hand only in lukewarm water.
- Dry the blade immediately after washing with a soft cloth.
- Use a wooden or suitable synthetic cutting board.
- Do not cut bones, frozen foods or other hard materials.
- Do not twist the blade during a cut and do not use it for prying.
- Store the knife in a protective sheath, knife stand or on a magnetic holder.
Need help choosing?
Contact us at +420 702 049 048, Mon–Fri, 7:30–16:00. We will help you choose the right shape, blade length and material according to the way you cook.
Frequently asked questions about BG-42 steel
Is BG-42 a powder steel?
Original BG-42 is not a powder steel. According to the material data sheet, it is a martensitic stainless steel produced using the double-vacuum VIM–VAR process.
What does VIM–VAR mean?
VIM means vacuum induction melting and VAR means vacuum arc remelting. The combination of both processes helps increase the cleanliness and homogeneity of the resulting steel.
Where was BG-42 developed?
BG-42 comes from the USA and was originally intended for critical aerospace components and highly loaded bearings. It was later also used in knife production.
Is BG-42 stainless?
Yes, BG-42 is a martensitic stainless steel with good corrosion resistance. Even a stainless knife, however, should not remain wet or dirty for long periods.
What hardness can BG-42 reach?
Depending on the selected heat treatment, knives may reach approximately 59–62 HRC. The decisive value is always the specification stated by the manufacturer of the particular knife.
How long does BG-42 hold an edge?
BG-42 offers good to high edge retention. The actual result is influenced by hardness, heat treatment, blade geometry, method of use and the cutting board used.
Is BG-42 better than SG2 or ZDP-189?
This cannot be determined in general. BG-42, SG2 and ZDP-189 have different compositions and production methods. The best choice depends on the desired edge retention, toughness, maintenance and intended use.
Is BG-42 difficult to sharpen?
Its wear resistance can make sharpening slightly slower. With a quality sharpening stone and a stable angle, however, it can be sharpened to a very functional edge.
Can a BG-42 knife go in the dishwasher?
We do not recommend it. A dishwasher can damage the fine edge, blade surface and handle material. Wash the knife by hand and dry it immediately.
Can a BG-42 knife be used to chop bones?
A standard BG-42 kitchen knife is not intended for chopping bones or frozen foods. For these tasks, use a robust cleaver specifically designed by the manufacturer for such use.
