твёрдость; жёсткость; стойкость
- hardness of water
- abrasion hardness
- alkaline hardness
- attrition hardness
- bicarbonate hardness
- Brinell hardness
- calcium hardness
- carbonate hardness
- diamond-pyramid hardness
- indentation hardness
- noncarbonate hardness
- permanent hardness
- Rockwell hardness
- scratch hardness
- temporary hardness
- total hardness of water
- Vicker's hardness
- water hardness
- wear hardness