Meaning
High-strength tool steel alloy characterized by chromium, molybdenum, and nickel additions provides the baseline for this grade. The designation 1.2738 identifies a pre-hardened plastic mould steel engineered for heavy-duty applications requiring high core strength and uniform hardness across large cross-sections. Vacuum degassing processes during initial melt stages reduce inclusions to improve the polishability of the final metal surface.
Consistent hardness levels throughout thick plates minimize warping during complex machining operations.
Thermal Stability
Large cavity blocks manufactured from this alloy maintain structural integrity when subjected to repeated heat cycles during high-speed injection moulding. Moulders select this grade for housings or automotive components where internal pressure causes potential fatigue in weaker alloys. Increased nickel content improves the toughness of the material during deep cavity milling.
Frequent tool maintenance intervals reduce overall production costs because this steel resists wear better than standard unalloyed grades.
Surface Finishing
Nitriding or chrome plating protocols integrate well with this composition to provide additional protection against abrasive resins or corrosive gases. Texture application remains consistent across the mould face due to the homogenous microstructure of the steel. Regrind incorporation during plastic processing increases the abrasive load on the tool, yet this grade withstands the mechanical stress without immediate degradation of the finish.
Polishing demands necessitate high attention to detail during the initial hardening phase to prevent localized soft spots.
Machining Efficiency
Pre-hardened delivery states allow machine shops to produce complex geometries without additional post-machining heat treatment. Lead times for tool fabrication shrink significantly when shops bypass the tempering step. Cutting parameters require adjustment based on the specific hardness range supplied by the mill to prevent tool tip damage.
Precision remains stable because the material experiences minimal dimensional shift after the completion of roughing cuts.
