Tungsten Carbide Grade Chart
Density, hardness, transverse rupture strength, grain size and composition for the grades produced here, with the ISO application code each one maps to.
Published Grade Properties
| Grade | Density g/cm³ | Hardness HRA | TRS MPa | Grain Size µm | Composition | ISO |
|---|---|---|---|---|---|---|
| YL10.2 | 14.4-14.6 | ≥92.2 | ≥4000 | 0.6-0.8 | 10% Co / 90% WC | K30 |
| YG6 | 14.85-15.05 | ≥90.0 | ≥2150 | 1.2-2.0 | 6% Co / 94% WC | K10 |
| YG6X | 14.85-15.0 | ≥92.0 | ≥1860 | 0.8-1.0 | 6% Co / 94% WC | K10 |
| YG8 | 14.65-14.85 | ≥89.5 | ≥2320 | 1.2-2.0 | 8% Co / 92% WC | K20 |
| YG10 | 14.5-14.6 | ≥85.5 | ≥2600 | 1.2-2.0 | 10% Co / 90% WC | K20 |
| YG15 | 14.0-14.1 | ≥85.0 | ≥2800 | 1.2-2.0 | 15% Co / 85% WC | — |
Grades also produced: YG8X, YG12, YG15X, YN6 and YN9. Ask for the data on these when you enquire.
Reading The Table
- Cobalt content sets the balance: less cobalt means harder and more brittle
- Grain size matters as much as cobalt: a fine grain lifts hardness and strength together
- TRS is the number that predicts chipping, not hardness
- Density drops as cobalt content rises because cobalt is lighter than tungsten carbide
- The ISO code lets a drawing written to K10 or K20 be matched to a grade here
Choosing By Failure Mode
- Uniform surface loss points at abrasion, so move to a lower cobalt grade such as YG6
- Edge chipping points at impact, so move to a higher cobalt grade such as YG15
- Pitting points at chemical attack, so the fluid chemistry has to be part of the brief
- Cutting tool blanks need fine grain, which is why YL10.2 is the usual rod grade
- When the failure mode is unclear, send the worn part and it can be read from the wear pattern
Where Each Grade Typically Goes
YL10.2
Solid carbide rod and cutting tool blanks, where a fine grain and TRS above 4000 MPa are what let a slender cutter survive.
YG6 and YG6X
Clean abrasive wear: nozzles, sleeves and plates where nothing is hitting the part, only sliding across it.
YG8 and YG10
General wear parts, bushes and valve trim, the middle ground where both abrasion and some shock are present.
YG15
Impact duty: dies, punches and parts that see pressure cycling, where toughness matters more than surface hardness.
YN6 and YN9
Nickel-bonded grades for service where cobalt binder is attacked chemically. Ask for data before specifying.
Not Sure
Send the worn part or a photograph of it with the operating conditions and a grade will be recommended with the quotation.
Grade Chart FAQ
What does the HRA number mean?
Rockwell A hardness. Higher numbers resist abrasion better. YL10.2 reaches at least 92.2 HRA while YG15 sits at 85.0 HRA, and the difference is cobalt content and grain size.
What is TRS and why does it matter?
Transverse rupture strength, in MPa. It is the practical measure of how much bending and shock the part takes before it breaks. YG15 gives at least 2800 MPa against 2150 MPa for YG6.
Which grade matches ISO K10 or K20?
YG6 and YG6X correspond to K10. YG8 and YG10 correspond to K20. YL10.2 corresponds to K30.
Why is YL10.2 harder than YG10 at the same cobalt content?
Grain size. YL10.2 is made on a 0.6 to 0.8 micron grain against 1.2 to 2.0 micron for YG10, which lifts it from 85.5 HRA to 92.2 HRA and TRS from 2600 to above 4000 MPa.
Do you produce grades outside this table?
Yes. YG6X, YG8X, YG12, YG15X, YN6 and YN9 are also produced. Describe the duty and the closest grade will be recommended.
Can you supply material test data with an order?
Not published on the source material. request the current material data when you send your enquiry.
Get A Grade Recommendation
Tell us what the part runs against, the temperature and whether the load is steady or cycling. The grade comes back with the price.