... Steel Gears Alloy Spring, High Elasticity Forged 40-chromium Alloy Piston Made our first rammer since 1983, with mature technology and ... Lighter WeightAlloy Steel Gears, for Longer DurabilityForged 40-Chromium Alloy Piston, Extreme High StrengthAlloy Spring, for higher elasticityForged Alloy Steel Plate ...