Pre-hardened mold steel materials suitable for injection molds, plastic mold cavities, cores, mold bases, sliders, inserts, and medium to large mold structural parts.
718 Mold Steel is a commonly used pre-hardened plastic mold steel, typically used for injection molds, mold cavities, mold cores, mold bases, sliders, inserts, and medium to large plastic mold parts. It has good machinability, polishing performance, dimensional stability, and overall strength, making it suitable for manufacturing plastic molds that require certain requirements for surface quality, dimensional stability, and mold lifespan. Mold steel 718 is usually supplied in a pre-hardened state, which reduces the risk of deformation during subsequent heat treatment.
By focusing on application scenarios, boundaries of advantages, and non-recommended scenarios, it helps sales, customer service, and quoting staff quickly determine whether the material meets current part requirements.
Stable pre-hardening state, good overall strength, good machinability, polishing performance, and dimensional stability, suitable for medium to large plastic molds, reducing the risk of heat treatment deformation, and suitable for making cavities and cores.
Injection mold cavities, plastic mold cores, mold inserts, sliders, inclined heads, mold bases, templates, medium and large plastic molds, automotive interior molds, home appliance shell molds, electronic product shell molds, daily necessities plastic molds, and low to medium batch injection molds.
High corrosion resistance molds, high mirror transparent molds, high-temperature die casting molds, high-strength stamping molds, strong acid and strong alkali environment parts, long-term outdoor exposed parts, food direct contact parts, medical implant parts, high wear resistance cold work molds, high red hardness hot work molds.
The following parameters come from product information and material knowledge fields, used for design review, quotation communication, and preliminary judgment before material selection.
| Material positioning | Pre-hardened mold steel materials suitable for injection molds, plastic mold cavities, cores, mold bases, sliders, inserts, and medium to large mold structural parts. |
|---|---|
| Precision performance | 718 Mold Steel is suitable for CNC precision machining, EDM, wire cutting, and grinding processes, achieving good cavity dimensional accuracy, hole position accuracy, and mating surface quality. Actual accuracy is affected by mold size, deep cavity structure, clamping method, cutting tool, machining path, EDM process, polishing amount, and mold trial and modification. High-precision mating surfaces, parting surfaces, slider mating surfaces, and insert positions should have separate tolerances. |
| Dimensional tolerances | The general dimensional tolerances of CNC machining 718 Mold Steel can be referenced as ± 0.02mm to ±0.10mm, while ordinary mold structural parts can be evaluated at ±0.05mm to ±0.20mm. Cavity, core, parting surface, insert position, slider mating position, and positioning hole can be further controlled according to mold requirements. This value is a conventional reference range and does not guarantee absolute tolerances for all structures. Actual values should be confirmed based on mold dimensions, processing methods, and polishing and mold repair requirements. |
| Minimum Wall Thickness | 718 Mold Steel when used as mold material, it is not recommended to design steel positions that are too thin. The recommended steel position for ordinary molds is no less than 1.0mm-1.5mm. The position near the cavity, inserts, sliders, and cooling water channels should be appropriately increased according to mold strength and machinability. Too thin steel positions are prone to deformation, cracking, or burn under machining, polishing, mold trials, or injection molding pressures. |
| Recommended wall thickness | It is recommended to retain sufficient steel thickness for ordinary mold cavities and core structures. For important pressure areas, screw connection points, insert fixing positions, and around cooling water channels, it is recommended to be at least 2.0mm to 5.0mm. Specifically, this should be determined based on mold size, injection pressure, product structure, and processing method. Medium and large molds should prioritize rigidity, heat dissipation, and assembly stability. |
| Minimum aperture | CNC drilling can achieve smaller hole diameters, but machining deep holes, water passage holes, and angled holes is more challenging. Standard hole diameters are recommended not less than 1.0mm; cooling water channels, ejector pin holes, screw holes, and positioning holes should be designed according to tool length, chip removal, machining accessibility, and mold strength. It is recommended to reserve machining space for deep holes and long waterways and avoid getting too close to the cavity surface. |
| Assembly clearance | 718 Mold Steel for mold assembly, standard positioning and assembly clearance can be precisely controlled to 0.01mm-0.05mm on one side; sliders, beveled ejectors, inserts, and movable structures should have reasonable clearance reserved according to movement mode, thermal expansion, lubrication, and wear. Ordinary non-precision structures can be evaluated as 0.05mm-0.20mm per side. The specific gap should be determined based on the mold structure and processing standards. |
| Detailed performance | 718 Mold Steel suitable for machining cavity details, steps, holes, grooves, chamfers, fillets, textures, parting surfaces, and insert fit structures. CNC machining and EDM can achieve more complex cavity details, while polishing and texturing enhance product surface effects. Overly fine sharp corners, deep narrow grooves, and thin steel positions increase machining difficulty and mold risk; it is recommended to optimize by rounding corners, insert splitting, or EDM machining. |
| Surface effect | 718 Mold Steel after CNC machining, it has a silver-gray metallic surface, with visible knife lines or machining patterns. After grinding and polishing, a good mold cavity surface can be obtained, suitable for molding ordinary plastic parts. EDM can produce a uniform spark texture surface, and texture processing can achieve leather, matte, and fine texture effects. If high mirror transparency is required, 718 may not be as stable as mirror-finish mold steels like S136 or NAK80. |
Based on material characteristics and suitable product ranges, customer needs are broken down into easier application directions to determine.
Injection mold cavities, plastic mold cores, mold inserts, sliders, inclined heads, mold bases, templates, medium and large plastic molds, automotive interior molds, home appliance shell molds, electronic product shell molds, daily necessities plastic molds, and low to medium batch injection molds.
Pre-hardened mold steel materials suitable for injection molds, plastic mold cavities, cores, mold bases, sliders, inserts, and medium to large mold structural parts.
718 Mold Steel is a pre-hardened material-plastic mold steel, which usually already has a certain hardness upon delivery, allowing direct CNC machining, EDM processing, polishing, and assembly, reducing the risk of deformation caused by subsequent refueling. It has better overall performance than ordinary P20 mold steel, making it suitable for medium to large molds and plastic product molds with certain surface quality requirements. However, 718 is neither a highly corrosion-resistant mold steel nor a high-mirror special steel. When dealing with corrosive plastics or transparent high-gloss products, careful material selection is necessary.
Based on wall thickness, hole position, assembly clearance, dimensional tolerances, and material usage risks, determine in advance whether the part structure is suitable for 718 Mold Steel.
Post-processing of 718 Mold Steel affects appearance, dimensions, hole position, assembly clearance, and usage validation results, and should be explained in advance during quotation, DFM review, and sample confirmation stages.
Post-processing should focus on appearance display, dimensional fitting, connection assembly, and testing verification. Parts involving assembly positions need to be reserved in advance for machining, coating, and trial assembly allowances.
For common issues such as threads, snaps, strength, temperature resistance, and weather resistance, identify in advance whether the material needs to be replaced or if another processing method should be used.
When customer demand exceeds 718 Mold Steel material boundaries, it is necessary to combine strength, temperature resistance, toughness, long-term stability, and mass production goals to promptly recommend alternative materials or processing technologies.
If better corrosion resistance is required, S136, NAK80, or stainless mold steels can be chosen; If higher mirror polishing is required, S136, NAK80, or high-purity mirror-finish mold steel can be chosen; If higher wear resistance is required, H13, Cr12MoV, or other high-wear mold steels can be selected; If you only use ordinary low-cost plastic molds, you can choose P20 or domestic pre-hardened mold steel; If complex conformal cooling structures are needed, metal 3D printing Tool Steel 1.2709 can be considered.
If customers need to produce plastic injection molds ranging from ordinary to medium-to-high standards and focus on processing stability, mold strength, polishing effect, and cost balance,718 Mold Steel is a more suitable choice. If the customer's product is a transparent part, high-gloss part, corrosive plastic part, or ultra-long mass-produced mold, priority should be given to evaluating S136, NAK80, H13, or other more suitable mold steel materials.
After uploading 3D/2D drawings and supplementing materials, quantities, tolerances, surface treatments, and delivery requirements, XPartsLab will provide next steps in 3D printing manufacturability, cost, and delivery pathways.
