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718H Pre-Hardened Mold Steel Multi-Layer Injection Mold Cavity Plate
This stacked square mold cavity plate is 5-axis CNC & sink EDM precision machined from 718H pre-hardened mold steel, integrated with large curved polished forming cavity, slide locking grooves, four-corner mold mounting through holes and distributed cooling pin holes. It serves as the core forming cavity carrier for large curved plastic product injection molds.
- Material: 718H Pre-Hardened Mold Steel
Hardness: HRC 28–32
Tolerance: ±0.003 mm
Surface Finish: High Gloss Mirror Polished Cavity
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Large Curved Cavity Mold Base Engineering
Integrated large smooth curved forming cavity adopts seamless transitional surface design to eliminate plastic flow marks, weld lines and sink marks during injection molding for large curved plastic housings. Perimeter slide positioning grooves reserve installation space for side core-pulling slide components to realize undercut demolding of complex plastic parts. Evenly distributed cooling holes surround the cavity to build a full-perimeter uniform cooling network, rapidly extracting heat from the large curved surface and shortening molding cooling cycle time. Four-corner thick mounting holes and dense positioning pin holes are machined with ultra-tight positional tolerance to ensure zero offset alignment after thousands of mold opening/closing cycles.
Three-layer stacked rigid block structure greatly resists bending deformation under high injection clamping pressure, maintaining stable dimensional consistency of large-size plastic finished products in continuous mass production.
Balanced Toughness 718H Pre-Hardened Mold Steel Construction
718H pre-hardened mold steel brings comprehensive advantages for large mold cavity plates:
- Delivered in pre-hardened state, eliminating secondary heat treatment and shortening mold manufacturing lead time
- Balanced hardness and impact fatigue toughness, resistant to surface denting and cracking under long-term repeated clamping impact
- Excellent polishing performance to achieve mirror-grade smooth cavity surface, directly producing high-gloss plastic parts without secondary post-processing
- Stable thermal conductivity balances mold temperature across the whole large curved cavity surface, reducing local hot spot defects
- Compatible with post surface processes including texture etching, gas nitriding and PVD hard coating to extend mold service life Perfect for medium-volume mass production of automotive interior trims, large electronic device housings and household appliance plastic shells with curved surfaces.
Custom Large Mold Cavity Engineering Support
- Custom cavity curved contour, stacked plate thickness, cooling channel layout and slide groove size based on customer 2D/3D CAD drawings of plastic products
- Optional surface upgrades: Mirror Polishing, Chemical Texture Etching, Gas Nitriding Anti-Wear Treatment, Anti-Corrosion Passivation
- DFM mold flow simulation consultation: cooling circuit balance optimization, gate position design, plastic shrinkage compensation for large curved surfaces
- Fast prototype cavity sampling and large-batch mold plate mass production delivery
Key Features & Advantages
- Large Integrated Curved Mirror Cavity: One-piece polished curved forming surface delivers flawless glossy plastic part appearance, minimizing post-mold polishing work.
- Perimeter Slide Groove Integration: Built-in slide mounting grooves simplify side undercut demolding mechanism assembly for complex plastic products.
- Full Surround Uniform Cooling Layout: Distributed cooling holes eliminate hot spots on wide curved cavity surfaces to cut reject rates and cycle time.
- Three-Layer Stacked Anti-Deformation Structure: Thickened multi-layer mold base withstands high injection clamping pressure without cavity deflection.
- Fully Customizable Cavity Geometry: Adjust curved depth, cavity outline and cooling hole distribution to match unique large plastic product molding demands.
Technical Specifications
| Parameter | Specification |
|---|---|
| Base Mold Material | 718H Pre-Hardened Mold Steel |
| Alternative Materials | S136 Stainless Mold Steel, NAK80 Mirror Mold Steel, P20 Mold Steel |
| Hardness | HRC 28–32 (As-delivered pre-hardened) |
| Dimensional Tolerance | ±0.003mm for cavity contour, hole position & plate flatness |
| Flatness | ≤0.004mm per 100mm plate length |
| Cavity Surface Roughness | Ra ≤0.02μm mirror polished finish; Outer surface Ra ≤1.6μm milled matte |
| Manufacturing Processes | 5-Axis CNC Milling, Sink EDM, Precision Deep Hole Drilling, Hand Mirror Polishing, Deburring |
| Surface Treatments | Mirror Polishing, Texture Etching, Gas Nitriding, PVD Hard Coating |
| Customization | 100% Fully Customized via CAD Drawings & Plastic Product Samples |
Applications
Automotive Interior Plastic Trim Molds
Large curved cavity plates for automotive dashboard covers, door panel plastic housings and armrest shells. Full-surround cooling balances temperature across wide curved parts to eliminate warpage and surface blemishes for automotive mass production.
Large Consumer Electronic Housings
Mold cavity blocks for TV back covers, monitor frames and large charger plastic casings. Mirror polished cavity produces scratch-free high-gloss electronic appearance parts with low post-processing cost.
Household Appliance Outer Shell Molds
Ideal for washing machine panels, air conditioner covers and kitchen appliance large plastic housings. Rigid stacked mold base maintains stable precision under long-cycle continuous injection molding.
Cosmetic Large Packaging Shells
Suitable for cosmetic storage box outer casings and large perfume bottle plastic mold inserts. Smooth mirror cavity ensures high-gloss luxury packaging surface effect.
Medical Large Equipment Plastic Housings
S136 stainless steel alternative mold plate meets medical hygiene standards, applied to medical instrument large plastic shell molds, resisting corrosion from medical plastic additives and mold cleaning agents.
