Comparison of Cemented Carbide Grades in Different Countries

Comparison of Cemented Carbide Grades from China, the US, Germany, Japan and ISO Standards

As a core material in global industrial processing, China, the United States, Germany, and Japan—major producers and users of cemented carbide—have each developed their own commonly used grade systems. The ISO (International Organization for Standardization) standard, as a globally recognized classification basis, provides a unified reference for aligning grades from different countries. Mastering the corresponding relationships between grades from these four countries and ISO standards can effectively avoid confusion in cross-border procurement and selection, improving work efficiency. This article uses plain language and clear tables to sort out the core correspondence between mainstream cemented carbide grades from the four countries and ISO standards, supplemented by brief characteristics of each grade system. It helps tungsten carbide industry practitioners quickly achieve the conversion of "grade from one country → ISO standard → grade from another country" to meet the needs of cross-border production and procurement.

1. Brief Introduction to the Four Countries' Cemented Carbide Grade Systems (Background Supplement)

Before understanding the correspondence, it is helpful to briefly familiarize yourself with the naming logic of the four countries' grades to better understand their connection with ISO standards:

1.1 Chinese Grade System

• Mainly composed of "letters + numbers", with core letters corresponding to the type of workpiece material, and numbers representing key component content (e.g., cobalt content);
• Common prefixes: Y (general prefix for cemented carbide), G (cobalt-based, corresponding to ISO K class for processing cast iron), T (titanium-based, corresponding to ISO P class for processing steel), W (tungsten-titanium-tantalum-based, corresponding to ISO M class for processing mixed materials);
• Examples: YG8 (Y=cemented carbide, G=cobalt-based, 8=8% cobalt content), YT15 (T=titanium-based, 15=15% TiC content).

1.2 US Grade System

• Based on the "AISI/ANSI" standard, adopting the form of "C + number" or "letter combination", where numbers or letters indirectly correspond to ISO performance grades;
• Core logic: Focus on classification by processing scenarios and performance, with a relatively direct correspondence between grades and ISO classes;
• Examples: C1 corresponds to ISO P01 (finish machining of steel), C2 corresponds to ISO P10 (semi-finish machining of steel), C5 corresponds to ISO K10 (processing of cast iron).

1.3 German Grade System

• Mainly "letter combination + numbers", representing brands (e.g., Bosch, Kennametal) and performance grades, with some grades directly marking the corresponding ISO grade;
• Core feature: Emphasizes performance segmentation, with suffixes often supplementing information such as coating and grain size;
• Examples: H13A corresponds to ISO P10, S20S corresponds to ISO M20, K40 corresponds to ISO K20.

1.4 Japanese Grade System

• Mainly based on enterprise grades from mainstream manufacturers (e.g., Sumitomo Electric, Kyocera, Mitsubishi Materials), with some referencing ISO standard naming or using letters to mark the type of workpiece material;
• Common prefixes: AC (Sumitomo), PA (Kyocera), TH (Mitsubishi), with suffix numbers representing performance grades;
• Examples: AC30S (corresponds to ISO P10), PA10 (corresponds to ISO K10), TH10 (corresponds to ISO N10).

Note: The grade systems of the four countries are not completely one-to-one with ISO standards. The following comparison focuses on "mainstream general grades". For special customized grades, confirmation should be made in conjunction with manufacturer parameters.

2. Core Comparison Table: Correspondence Between Four Countries' Grades and ISO Standards

The following is a comparison between the most commonly used ISO classes (P/M/K/N/S classes) and mainstream grades from the four countries, supplemented by applicable scenarios for direct reference:

Table Supplementary Notes:

1. In Chinese grades, "X" represents "fine grain" (e.g., YG6X has finer grains and higher hardness than YG6), suitable for finish machining;
2. German and Japanese grades often have manufacturer-specific suffixes (e.g., "S" for coating, "M" for mixed processing), but the core performance is consistent with the ISO grade;
3. In the US C-series grades, smaller numbers indicate higher hardness (suitable for finish machining); larger numbers indicate stronger toughness (suitable for rough machining), which is consistent with the ISO grade logic.

3. Practical Comparison Skills: 3 Key Points to Avoid Confusion

3.1 First Lock the ISO Grade, Then Find the Corresponding Grade

In cross-border selection, first clarify the processing requirements → determine the ISO class (e.g., processing stainless steel → ISO M class) and grade (finish machining → M10), then find the corresponding grades from the four countries through the table. This is more reliable than directly memorizing "grade from one country corresponds to grade from another country".

3.2 Note "Approximate Correspondence" Rather Than "Exact Equivalence"

Even if grades from different countries correspond to the same ISO grade, there may be differences in component details (e.g., grain size, binder distribution). Before actual use, refer to the performance parameters provided by the manufacturer (e.g., hardness HRA, bending strength) to avoid relying solely on grade comparison.

3.3 Comparison Logic for Coated Grades

For coated cemented carbide (e.g., TiAlN coating), grades from the four countries usually add a suffix to the base grade (China: YT15C, Germany: H13AC, Japan: PA20C). Their ISO correspondence is consistent with the uncoated version, and only the "coating type" supplementary information needs to be noted.

Example: Practical Application Scenario

A factory needs to process 304 stainless steel (mixed materials, corresponding to ISO M10 grade) and originally uses Chinese grade YW1. Now it needs to purchase German-made tools → find the corresponding German grade S10S through the table, which can be directly used as a procurement reference; if the customer requires Japanese grades, Sumitomo AC20M or Kyocera PA30M can be recommended.

4. Common Misunderstandings: Avoid These "Comparison Pitfalls"

4.1 Confusing "Component Correspondence" with "Performance Correspondence"

Chinese YG8 (8% cobalt content) and German K20 correspond to the same ISO K20 grade, but the cobalt content of German K20 may be 7% or 9%—ISO standards focus on "performance grade" (hardness, toughness) correspondence rather than exact component consistency. The core is to look at actual performance parameters.

4.2 Ignoring Manufacturer-specific Special Grades

Some manufacturers have their own customized grades (e.g., Mitsubishi's TH series, Kennametal's KC series). Although not included in general comparisons, the corresponding ISO grades are usually marked in the manufacturer's manual. During procurement, direct consultation with the manufacturer can obtain benchmarking information.

4.3 Forcing "Old Grades" to Correspond to ISO Standards

Some countries have old grade systems (e.g., the early Chinese terms "tungsten-cobalt type" and "tungsten-titanium-cobalt type"). It is recommended to first update old grades to current general grades before comparing with ISO standards to avoid errors.

Conclusion: The Comparison Table is a "Quick Tool for Cross-border Selection"

Although the cemented carbide grade systems of China, the US, Germany, and Japan are different, the ISO standard, as a "universal language", has built a bridge for mutual conversion. The comparison table in this article focuses on the most common scenarios, and there is no need to delve into complex component differences to meet the needs of daily selection, procurement, and customer communication. For example, when a domestic manufacturer quotes a German customer, it can directly provide "ISO P10 grade (corresponding to German H13A)" to make communication more efficient; when purchasing Japanese tools, alternative grades can also be quickly locked through ISO grades.

As a tungsten carbide industry practitioner, it is recommended to save this comparison table for future use. For special grades or customized needs, further confirmation can be made in conjunction with the manufacturer's parameter manual. If you need to supplement the grade comparison for certain special materials (e.g., difficult-to-machine alloys, non-ferrous metals) or obtain exclusive grade benchmarking information from a specific manufacturer, please feel free to contact us for customized supplementary content.