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Advanced Overmolding Services

Overmolding is essential for tooling, electronics, and healthcare industries combining materials. Common products:
  • Soft-grip tool handles
  • Sealed electronic connectors
  • Medical device grips
  • Dual-material automotive buttons
  • Wear-resistant gear covers
  • Consumer product ergonomic interfaces

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Advanced Manufacturing Capabilities

Integrating Engineering Expertise, Advanced Manufacturing Processes, and Flexible Production Capabilities to Support Product Development from Initial Prototypes to Scalable Production.

Insert Overmolding

Precisely encapsulates metal/plastic inserts via secondary injection (±0.2mm tolerance). Essential for automotive bushings and waterproof connectors.

Double Shot Molding

Combines two materials in one cycle (e.g., ABS+TPE) with <0.05mm layer precision. Standard for ergonomic tool handles and electronics, enabling enhanced design flexibility.

Co-Injection Molding

Simultaneously molds core/skin layers (e.g., recycled PP core + virgin ABS skin), reducing weight by 15-30%. Critical for food packaging and automotive parts.

Sequential Molding

Multi-stage process for complex geometries (e.g., rigid-to-flexible transitions). Cycle times increase 20-40% versus standard methods, enabling advanced material combinations.

Our Advanced Overmolding Parts

Combining TPE/TPU with rigid substrates through multi-shot molding, we create ergonomic grips, seals, and vibration-damping components. Our robotic cells maintain 0.05mm bonding accuracy for medical devices and industrial controls.

Insert Overmolding Parts
  • 10+ Years of Overmolding Services
  • Tolerances as tight as ±0.0004 in.（0.01mm）
  • MOQ as low as only 1 pc.
  • Lead time:T1 samples as fast as 2 weeks
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Double Shot Molding Parts
  • 10+ Years of Overmolding Services
  • Tolerances as tight as ±0.0004 in.（0.01mm）
  • MOQ as low as only 1 pc.
  • Lead time:T1 samples as fast as 2 weeks
Get a Quote
Functional Overmolding Parts
  • 10+ Years of Overmolding Services
  • Tolerances as tight as ±0.0004 in.（0.01mm）
  • MOQ as low as only 1 pc.
  • Lead time:T1 samples as fast as 2 weeks
Get a Quote

Overmolding Materials

Bonding TPE/TPU (Shore 30A-90A) to PC/ABS substrates with chemical/mechanical adhesion solutions. Medical-grade silicone overmolding available for soft-touch surfaces compliant with FDA 21 CFR and ISO 13485 standards.

Metals

Lightweight, high thermal conductivity, Excellent Machinability, Superior Dimensional Stability, Tight-Tolerance Capable, Perfect for Complex CNC Milling and Turning.
Price: $0
Lead Time: < 5 days
Tolerances: ±0.005″ (±0.125mm)
Max part size: 200 cm x 80 cm x 100 cm

Extremely lightweight (67% aluminum density), good vibration damping, requires surface treatment.
Price: $0
Lead Time: < 10 days
Tolerances: ±0.005″ (±0.125mm)
Max part size: 200 cm x 80 cm x 100 cm

Excellent malleability, corrosion-resistant, decorative finishes, suitable for intricate stamped panels.
Price: $0
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High electrical conductivity, soft yet work-hardening, requires annealing during multi-stage forming.
Price: $0
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Cost-effective formability, high strength-to-weight ratio, requires anti-rust coating for exposed edges.
Price: $0
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Corrosion-resistant, retains strength after welding, maintains integrity in harsh environments.
Price: $0
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Aerospace-grade strength, biocompatible, seawater corrosion resistance, difficult to machine.
Price: $0
Lead Time: < 10 days
Tolerances: ±0.005″ (±0.125mm)
Max part size: 200 cm x 80 cm x 100 cm

Lightweight, high thermal conductivity, Excellent Machinability, Superior Dimensional Stability, Tight-Tolerance Capable, Perfect for Complex CNC Milling and Turning.
Price: $0
Lead Time: < 5 days
Tolerances: ±0.005″ (±0.125mm)
Max part size: 200 cm x 80 cm x 100 cm

Plastics

Fast-flowing melt, low shrinkage (0.4-0.7%), requires pre-drying (80°C/4h), ideal for automotive dashboards and consumer electronics housings.
Price: $0
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High melt viscosity (300-350°C processing), moisture-sensitive (0.02% max), optical-grade clarity for LED lenses and medical device components.
Price: $0
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Crystallization-sensitive cooling (80-120°C mold), high dimensional stability, precision gears and fuel system valves.
Price: $0
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Moisture absorption (2.5-3.5%) requires post-molding annealing, self-lubricating bushings and automotive cable ties.
Price: $0
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Extreme processing temps (380-400°C), low shrinkage (0.1-0.3%), aerospace bushings and surgical sterilization trays.
Price: $0
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Heat distortion resistance (150°C), electrical insulation, glass-fiber reinforced automotive connectors.
Price: $0
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Aerospace-grade strength, biocompatible, seawater corrosion resistance, difficult to machine.
Price: $0
Lead Time: < 10 days
Tolerances: ±0.005″ (±0.125mm)
Max part size: 200 cm x 80 cm x 100 cm

Lightweight, high thermal conductivity, Excellent Machinability, Superior Dimensional Stability, Tight-Tolerance Capable, Perfect for Complex CNC Milling and Turning.
Price: $0
Lead Time: < 5 days
Tolerances: ±0.005″ (±0.125mm)
Max part size: 200 cm x 80 cm x 100 cm

Low melt strength (LDPE: 160-240°C), high flow rate for thin-wall containers and chemical-resistant pipeline fittings.
Price: $0
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Low density (0.9g/cm³), living hinge capability, disposable syringes and automotive HVAC ducts.
Price: $0
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High mold temperature (60-80°C) reduces internal stress, low warpage, replaces glass in automotive taillights and cosmetic packaging.
Price: $0
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Overmolding Services Tolerances and Standards

With professional project managers and engineers in overmolding, we help to make your project come true from design to production. Our’s overmolding service is dedicated to ensuring your product’s better performance.

Surface Finishes by Material

Different materials require different finishing processes. Explore the most suitable surface finishes for aluminum, stainless steel, titanium, brass, copper, engineering plastics, and more to achieve the ideal balance of protection, appearance, and performance.

As Machined
As Machined
Description: Standard finish with surface roughness of 3.2 μm (126 μin), removes sharp edges and deburrs parts cleanly. Key Use: Functional parts requiring no post-processing (e.g., brackets, gears). Process Tolerance: Dimensional ±0.1 mm, Ra 3.2±0.5 μm Process Specifications: ISO 2768-m standard, burr height ≤0.05 mm
Anodizing
Anodizing
Description: Electrochemical oxide layer for corrosion resistance and aesthetics. Process Compatibility: Post-machining surface treatment Key Use: Aerospace components, consumer electronics (e.g., phone frames). Process Tolerance: Coating thickness 10-25 μm±2 μm, color consistency ΔE≤1.5 Process Specifications: MIL-A-8625 or ISO 7599, sealing pH 5.5-6.5
Alodine
Alodine
Description: Chemical film for corrosion protection and paint adhesion. Process Compatibility: Post-cleaning chemical immersion Key Use: Aviation and automotive electrical housings. Process Tolerance: Film thickness 0.5-3 μm, visual uniformity Process Specifications: Immersion time 3-10 min, bath temp. 20-30℃
Black Oxide
Black Oxide
Description: Thin magnetite layer for corrosion resistance and reduced glare. Process Compatibility: Post-machining chemical treatment Key Use: Tools, firearms, automotive fasteners. Process Tolerance: Coating thickness 0.5-1.5 μm, salt spray ≥24 hrs Process Specifications: Alkaline bath pH 13-14, process time 5-30 min
Brushed Finish
Brushed finish
Description: Linear abrasive finish for decorative texture. Process Compatibility: Manual/CNC abrasive belts Key Use: Appliance panels, architectural trims. Process Tolerance: Texture depth 0.05-0.2 mm, angle deviation ≤5° Process Specifications: Abrasive belt grit 80-240, feed speed 10-30 m/min
Etching
Etching
Description: Chemical/mechanical removal for micro-texturing or marking. Process Compatibility: Laser/chemical masking Key Use: Circuit boards, decorative logos. Process Tolerance: Etch depth 0.01-0.5 mm±5%, alignment ±0.1 mm Process Specifications: Etchant concentration 10-30%, laser power 20-100 W
Electroless Plating
Electroless Plating
Description: Uniform metal coating (e.g., nickel) without electricity. Process Compatibility: Chemical bath deposition Key Use: Wear-resistant industrial valves, connectors. Process Tolerance: Coating thickness 5-50 μm±5%, porosity ≤5/cm² Process Specifications: Bath temp. 85-95℃, pH 4.5-5.5
Electroplating
Electroplating
Description: Electrochemical metal coating (e.g., chrome, zinc) for durability. Process Compatibility: Post-machining electrodeposition Key Use: Automotive trim, jewelry. Process Tolerance: Coating thickness 5-25 μm±2 μm, adhesion ≥4B (ASTM B571) Process Specifications: Current density 1-10 A/dm², bath temp. 40-60℃
Electrophoretic Coating
Electrophoretic
Description: Polymer coating via electric field for corrosion resistance. Process Compatibility: Post-cleaning immersion Key Use: Automotive frames, HVAC components. Process Tolerance: Coating thickness 15-30 μm±3 μm, edge coverage ≥80% Process Specifications: Voltage 50-300 V, cure 160-200℃×20 min
Electropolishing
Electropolish
Description: Electrochemical finishing for smoother, cleaner, corrosion-resistant surfaces with a bright finish. Process Compatibility: Post-machining. Key Use: Medical, pharmaceutical, semiconductor, and aerospace parts. Process Tolerance: Material removal 5–25 μm, Ra 0.1–0.4 μm. Process Specifications: ASTM B912 or ISO 15730 with controlled electrolyte and current density.
Grinding
Grinding
Description: Precision abrasive finish for tight tolerances. Process Compatibility: Surface/cylindrical grinding Key Use: Bearing races, hydraulic shafts. Process Tolerance: Dimensional ±0.005 mm, Ra 0.4-0.8 μm Process Specifications: Wheel grit 60-120, coolant flow 5-20 L/min
Heat Treatment
Heat Treatment
Description: Thermal process to alter material hardness/toughness. Process Compatibility: Post-machining quenching/tempering Key Use: Gears, cutting tools. Process Tolerance: Hardness HRC 45-60±2, distortion ≤0.1% Process Specifications: Quench temp. 800-1000℃, temper time 1-4 hrs
Knurling
Knurling
Description: Diamond or linear pattern for improved grip. Process Compatibility: CNC lathe rolling Key Use: Handles, adjustment knobs. Process Tolerance: Pattern depth 0.2-0.5 mm, pitch ±0.05 mm Process Specifications: Roller pressure 200-500 N, feed 10-50 mm/min
Laser Engraving
Laser Engraving
Description: Permanent marking via laser ablation. Process Compatibility: Post-processing laser systems Materials: Metals, plastics, wood Key Use: Serial numbers, branding on industrial parts.
Overmolding
Overmolding
Description: Molding soft material (TPU/silicone) over rigid inserts. Process Compatibility: Injection molding Materials: Plastics, metals (as inserts) Key Use: Ergonomic handles, waterproof seals. Process Tolerance: Overmold thickness 1-5 mm±0.2 mm, bond strength ≥5 MPa Process Specifications: Injection pressure >5 MPa, mold temp. 40-80℃
Polishing
Polishing
Description: Mirror-like finish via abrasive compounds. Process Compatibility: Manual/robotic buffing Key Use: Medical instruments, luxury fixtures. Process Tolerance: Ra 0.025-0.1 μm, gloss ≥90 GU Process Specifications: Wheel speed 1000-3000 rpm, compound grit 2000-5000
Passivation
Passivation
Description: Acid treatment to remove free iron and enhance corrosion resistance. Process Compatibility: Post-cleaning chemical immersion Key Use: Surgical tools, food processing equipment. Process Tolerance: Film thickness 0.001-0.01 μm, salt spray ≥96 hrs Process Specifications: Nitric acid 20-50%, process time 20-60 min
Powder Coating
Powder Coating
Description: Electrostatic polymer powder cured into durable film. Process Compatibility: Post-cleaning spray and bake Key Use: Outdoor furniture, automotive wheels. Process Tolerance: Coating thickness 60-120 μm±10 μm, ΔE≤1.0 Process Specifications: Voltage 30-90 kV, cure 180-200℃×15 min
Phosphating
Phosphating
Description: Phosphate layer for lubrication and paint adhesion. Process Compatibility: Chemical immersion Key Use: Engine components, firearm parts. Process Tolerance: Coating weight 2-5 g/m², crystal size ≤5 μm Process Specifications: Bath pH 2-4, process temp. 40-70℃
Painting
Painting
Description: Liquid coating for color and protection. Process Compatibility: Spraying/dipping Materials: Metals, plastics Key Use: Consumer electronics, automotive body panels. Process Tolerance: Coating thickness 20-50 μm±5 μm, adhesion ≥3B (ASTM D3359) Process Specifications: Spray pressure 0.3-0.6 MPa, cure 80-120℃×30 min
Sandblasting
Sand blasting
Description: Abrasive jet finish for uniform matte texture. Process Compatibility: Post-machining blasting Materials: Metals, glass, stone Key Use: Architectural facades, engine blocks. Process Tolerance: Ra 1.6-6.3 μm, coverage ≥95% Process Specifications: Grit size 80-120, air pressure 0.4-0.7 MPa
Teflon Coating
Teflon Coating
Description: Non-stick, chemical-resistant polymer layer. Process Compatibility: Spraying/baking Materials: Metals, ceramics Key Use: Cookware, chemical valves. Process Tolerance: Coating thickness 15-50 μm±5%, non-stick cycles ≥1000 Process Specifications: Sintering 360-400℃, cure time 10-30 min
Tumbling
Tumbling
Description: Barrel polishing for edge rounding and deburring. Process Compatibility: Vibratory/rotary barrels Materials: Metals, plastics Key Use: Jewelry, small hardware components. Process Tolerance: Edge radius R0.1-0.5 mm, weight loss ≤1% Process Specifications: Media size 3-10 mm, speed 10-30 rpm, time 1-12 hrs
SPI Finish
SPI Finish
Description: Graded texture (e.g., SPI-A1 for glossy, SPI-C3 for matte). Process Compatibility: EDM, polishing Materials: Tool steel, aluminum molds Key Use: Plastic injection molds for consumer products. Process Tolerance: Ra 0.05-1.6 μm, texture replication ≥90% Process Specifications: SPI-SPE-1 standard, EDM current 5-50 A

What is Overmolding?How Does Overmolding Work?‌

Overmolding is a ‌multi-material injection molding process‌ where a substrate (typically rigid plastic or metal) is encapsulated or coated with a second material (often soft elastomer or thermoplastic) to create a single, integrated component‌. This technique enhances functionality by combining properties like grip, shock absorption, and waterproofing, commonly used in tool handles, medical devices, and consumer electronics‌.

  • Substrate Preparation‌:A base part (e.g., rigid plastic or metal insert) is produced via injection molding, machining, or stamping‌. The substrate may undergo surface treatment (e.g., plasma etching) to improve adhesion‌.
  • Mold Setup‌:The substrate is placed into an overmolding mold, which is precision-aligned to ensure proper material flow and bonding‌.
  • Material Injection‌:A secondary material (e.g., TPE, silicone, or urethane) is injected into the mold, enveloping the substrate.Temperature and pressure are tightly controlled to bond materials chemically or mechanically‌.
  • Cooling & Ejection‌:The combined part cools within the mold to solidify the overmolded layer.Ejector pins release the finished component, ready for post-processing‌.

Success Stories of Overmolding Projects

FAQs

What is the thickness of the overmolding?‌

We standards recommend maintaining uniform wall thickness (0.711-3.81mm optimal range) across both substrate and 

overmold. This ensures: 1) consistent cycle times by balancing cooling rates, and 2) reliable adhesion through controlled material flow and 

shrinkage characteristics in production.

Our decade of injection molding expertise dictates critical overmolding parameters: The overmold thickness must not exceed the substrate’s,

 and its melt temperature should be 20-30°C lower than the base material. Chemical adhesion is generally ineffective – mechanical interlocking and thermal 

compatibility drive successful bonding.

Overmolding traditionally requires transferring a pre-formed substrate to a secondary mold for material encapsulation, creating a mechanical bond.

 2K molding (two-shot) accomplishes this in a single cycle using a rotary mold, offering superior efficiency and bond strength. While often used 

interchangeably, 2K represents the advanced, single-machine version of overmolding technology.