cylindrical grinding, flat grinding, internal grinding operations
producing of details for bearing industry etc.
sharpening of metal cutting tools
gear grinding operations
thread-grinding operations
producing parts for turbine etc.
instrument steel (P18, P6M5 etc.)
bearing steel
titanium alloy
heat-resistant steel
alloy-threated steel
Table 1. Types of hardness
| Group of Hardness | Designation in accordance with ISO Standards |
|---|---|
| Soft | J, K, L |
| Medium-soft | M, N, O |
| Hard | P, Q, R, S |
Grinding of hard materials – soft bond. The soft bond also could be used for grinding of soft and yielding materials, such as heatproof and nonferrous alloys.
For rough grinding should be used wheels with harder bond.
In case of speed rising client should decrease the hardness of the bond.
In case of large contact of grinding wheel with processed surface should be used softer bond.

FOR VITRIFIED BONDED WHEELS
| Grinding Method | Grit Size | Hardness |
|---|---|---|
| Surface grinding: | ||
| Peripheral grinding, Ra 0,32 – 1,25 | B91 … B126 | L – M |
| Face grinding, Ra 0,16 – 0,63 | B54 … B76 | K – L |
| Internal grinding | B64 … B126 | O – R |
| Cylindrical grinding: | ||
| In-feed grinding, Ra 0,32 – 1,25 | B126 … B151 | N – O |
| Traverse grinding Ra 0,16 – 0,63 | B54 … B107 | M – N |
| Gear grinding: | ||
| Module < 3 mm | B76 … B91 | L – N |
| Module > 3 mm | B107 … B151 | K – M |
| Thread grinding: | ||
| Pitch of thread 0,5 – 0,8 mm | B16 … B25 | P – S |
| Pitch of thread 0,8 – 1 mm | B25 … B40 | O – P |
| Pitch of thread 1 – 1,5 mm | B40 … B54 | M – N |
| Pitch of thread > 1,5 mm | B54 … B76 | L – N |
| Vitrified Bonds | Hardness | Edge Resistance | Porosity | Recommendation for Material Hardness |
|---|---|---|---|---|
| XBCK4 | K | high | low | more than 55 HRC |
| XBCL4 | L | high | low | |
| VBCN5 | N | high | low | less than 55 HRC |
| VBCM5 | M | |||
| VBCO5 | O | high | low | less than 55 HRC |
| VBCP5 | P | |||
| VBBO5 | O | low | high | less than 60 HRC |
| VBBP5 | P |





Implementation & Consulting
Our specialists are at your disposal for quotes and advice in selecting the right products. At NUBERT & CO, we combine advanced technology and global expertise to provide solutions that transform industrial processes, ensuring efficiency and superior quality.
At NUBERT & CO, we combine advanced technology with global expertise to deliver solutions that transform industrial processes.
Contact us for a customized solution
Our specialists are at your disposal for quotes and advice in selecting the right products. At NUBERT & CO, we combine advanced technology and global expertise to provide solutions that transform industrial processes, ensuring efficiency and superior quality.
© NUBERT & CO S.R.L,
CUI: 17867946, Nr. inreg; J40/14104/2005