Demystifying Carbide Grades: From ISO to YG – A Complete Guide for Metalworkers

Every day, we see customers overwhelmed by the complexity of choosing the right carbide grade. Is P20 better than K30? When should you choose YT14 over YG8?

At Suntera Carbide, we believe knowledge is the first step to precision. Today, we are pulling back the curtain on the “secret code” of carbide inserts.

The ISO Universal Language
The International Standard (ISO) simplifies the world into three main categories based on chip formation:

  • P (Blue): For steel and long-chip materials. High pressure, high temperature.

  • M (Yellow): For stainless steel and difficult-to-machine alloys.

  • K (Red): For cast iron, chilled iron, and non-ferrous metals (short chips).

The Balance of Power: Wear vs. Toughness
Every carbide grade is a sacrifice. You cannot max out both attributes.

  • Low Numbers (05–20): Maximize hardness. Ideal for finishing, high speeds, and stable conditions.

  • High Numbers (30–45): Maximize impact resistance. Ideal for roughing, interrupted cuts, and unstable fixtures.

Translating Chinese National Standards (GB/T)
The Chinese market often uses YG, YT, or YW codes. Here is your reference table:

Chinese GradeCompositionISO EquivalentBest Use
              YG8                         WC + Co          K30-K40                        Cast iron, Aluminum, Roughing
            YT14                   WC + TiC + Co           P20-P30                           Steel, Medium machining
        YW1 / YW2               WC + TiC + TaC + Co           M10-M30                    Stainless steel, High-temp alloys       

Our Recommendation to Customers:
Start with the ISO system to define your material and operation. Then, use our chart above to cross-reference to local YG/YT grades. If you are still unsure, choose the “middle ground” (P20 or YT14) – it is the “duct tape” of the machining world.

For a detailed quote on your specific application, contact our engineering team today.