caps
Caps (rotor caps and end discs) are available in manganese or alloy steel.
Austenitic manganese steel:
| Chemical composition | C (Max) | Mn | Si | Cr | P | S |
| 1.05-1.20 | 11.00-19.00 | ≤1.00 | 1.50-2.50 | ≤0.06 | ≤0.10 | |
| Mechanical properties
| UTS (KSI) | YS (KSI) | EL% | Hardness(BHN) | Charpy V-notch(room temp) | |
| 90-140 | 50-70 | 24-40 | 200-250 | 90-160 ft.lb | ||
Low Alloy steel:
| Chemical composition | C (Max) | Mn | Si | Cr | P | S | Mo | Ni |
| 0.26-0.34 | 0.30-0.60 | ≤0.40 | 1.80-2.20 | ≤0.035 | ≤0.35 | 0.30-0.50 | 1.80-2.20 | |
| Mechanical properties
| Hardness(BHN) | Impact strength(kg*m/cm2) | ||||||
| ≧450 | 5.5 | |||||||