Professional Manufacturer for Plastic Injection Molding

Injection Molding Services

Molded prototypes and low-volume production parts in as fast as 1 day

High Quality Custom Injection Molding

Yiannopoulos delivers high-quality, on-demand injection molded parts. Injection molding is the cheapest process to make a plastic part at scale by offering consistent quality for mid-to-high volume manufacturing. Molding also has the highest variety of materials, colors, and configurations compared to CNC machining or even 3D printing. Beyond materials, injection molded parts can have custom cosmetics, polishes, or surface textures.

Yiannopoulos takes a “have it your way” approach to molding. We specialize in complex projects, typically requiring side action or hand loaded inserts. Our goal is to provide a long term solution, moving beyond rapid prototyping, with dedicated project managers and engineering experts to communicate through all project stages from design to production.


Yiannopoulos’ injection molding services include:

  • 24-hour quoting with design for manufacturing (DFM) feedback
  • Large domestic partner network as well as international options
  • Single point of contact per customer
  • Expert consultation
  • Single, multi-cavity, and family mold options
  • Insert molding and overmolding
  • Most plastic materials, including custom sourcing and matching
  • Press availability from 30 to 1,100+ tons
  • Part inspection, including FAI and PPAP options
  • Customer-owned tooling

Is your project ready for injection molding? Upload your 3D model for a free quote.

Advantages of Injection Molding

Injection molding is an excellent option for the large-scale production of plastic parts and components. The advantages of using injection molding include:
  • Efficiency: The mold injection process is highly efficient, facilitating short lead times for large orders.
  • Superior detail: The high pressure of injection ensures that the melted material reaches every crevice of the mold before curing. This enables design engineers to incorporate complex geometrics and intricate elements into their designs.
  • Affordability: Fast and efficient production ensures a low cost per part, while high production volumes produce further economies of scale. Aluminum a cost-effective and readily available material can be used for tools to control costs.
  • High-volume production: Injection molding with steel molds can facilitate high-volume production of parts into the millions.
  • High tensile strength: Injection-molded parts may be reinforced by adding fillers into the liquid resin that improves tensile strength. 
  • Ready-to-go finish: With the proper treatment, injection-molded parts come out of the mold with a smooth finish that requires no further refinement.

The Injection Molding Process

During the injection molding process, material is melted and mixed in a barrel where a reciprocating screw melts the material and feeds it into a split mold. The liquid material is then injected into a prototype mold cavity at high pressure to force it into all mold cavities before it cools and solidifies into the predetermined design shape.

This process is highly effective for the large scale production of industrial parts and components, and allows for the creation of products with multiple materials using repeated injection methods. Prototype injection molding wastes less material than other manufacturing processes and saves time by reducing the number of steps necessary to produce a given product.

Why engineers use Yiannopoulos for injection molding

Instant quoting & DfM feedback
Build and edit your quote online. Review your parts for manufacturability and assess the cost of different materials, processes and lead times for your project in real time.
Readily available capacity
Readily available capacity
Benefit from our network of 250 manufacturing partners to access instantly available capacity. Our manufacturing partners are both local and overseas.
Quality & reliability
Quality & reliability
Dedicated 3D Hubs team to ensure your parts consistently meet your quality expectations. We also offer phone, email and chat support for any concerns or questions you may have.

Our injection molding capabilities

Our network of Manufacturing Partners gives you easy access to diverse capabilities to serve all your manufacturing needs.
Name Description
Minimum order quantity 100 runs
Mold material Tool Steel P20, Carbon Steel S50C, Aluminum
Mold types Rapid tooling, production tooling
Mold storage Minimum 2 years
Mold lead time 2-3 weeks (Rapid tool), 4-5 weeks (Production tool)
Quality assurance Inspection reports included, full dimensional report and material certifications available upon request.
Design verification program Similar to First Article Inspection, you will receive 2 sets of parts upon the machining of the mold to test fit before continuing with full production.
Mold remachining We can remachine the molds should any changes be required, changes to be reviewed on a case by case basis.
Reorders Unit price is based on the quantity required for the reorder with an additional set up fee of $150/€100.
Additional technical support Dedicated 3D Hubs Mechanical Engineer for technical support.

Our injection molding service

Our injection molding service allows you to seeminglessly move from prototyping to end-part production.
Name Description
Rapid Tooling Molds with aluminum inserts with a life time of up to 20,000 runs. Machined in typically 2-3 weeks.
Production tooling Traditional hard molds, machined in typically 4-5 weeks.
Single cavity molds Molds containing only one cavity, producing one unit per run.
Molds with side-action cores Cores slide out of the part from the side before it is ejected from the mold. This allows for undercuts to be molded.
Multi-cavity molds Multiple identical cavities are machined into the mold tool. This allows for more parts to be produced per shot, minimizing the unit costs.
Family Molds Several parts are designed into the same mold tool. This allows for the minimization of tooling costs.
Insert molding Inserts are placed into the mold and molding occurs around them. This allows for inserts such as helicoils to be molded in your design.
Overmolding Premade parts are placed into the mold to mold over them. This allows for multi-material injection molding.

Available materials for plastic injection molding

All thermoplastics can be injection molded. Some thermosets and liquid silicones are also compatible with the injection molding process.
Common thermoplastic with high impact resistance, low-cost & low density. Vulnerable to solvents.
Nylon (PA 6)
Engineering thermoplastic with excellent mechanical properties and high chemical & abrasion resistance. Susceptible to moisture.
Blend of two thermoplastics resulting in high impact strength, excellent thermal stability, and high stiffness. Vulnerable to solvents.
Polyurethane (PU)
Thermoplastic with high impact strength and good mechanical properties & hardness. Suitable for molding parts with thick walls.
Polypropylene (PP)
Polypropylene (PP)
The most common Injection molding plastic. Excellent chemical resistance. Food-safe grades available. Not suitable for mechanical applications.
Polyethylene (PE)
Polyethylene (PE)
Lightweight thermoplastic with good impact strength & weather resistance. Suitable for outdoor applications.
Polystyrene (PS)
Polystyrene (PS)
The Injection molding plastic with the lowest cost. Food-safe grades available. Not suitable for mechanical applications.
Polyvinyl chloride (PVC)
Polyvinyl chloride (PVC)
Light weight plastic with good mechanical strength and abrasion resistance. Generally used in building and construction applications.
High-performance engineering thermoplastic with excellent strength and thermal & chemical resistance. Used to replace metal parts.

Additives and fibers

Yiannopoulos offers additives and reinforcements as options for your plastics parts.
Name Description
UV absorbers Absorb UV radiation, slowing down the degradation of the material when used outdoors.
Flame retardants Prevent ignition and inhibits spread of fire.
Plasticizers Increase flexibility and promotes plasticity, reducing brittleness of the material.
Colorants Used to color plastics.
Carbon fibers Increase strength, toughness, and rigidity of the material at the expense of making the material more brittle.
Glass fibers Increase strength, toughness, and rigidity of the material at the expense of making the material more brittle. It is more flexible than carbon fibers.

Available surface finishes for injection molding

Injection molded parts are not usually post-processed, but the mold itself can be finished to affect the surface finish of the molded part.

This way aesthetic needs or technical requirements can be achieved.
  Name SPI Standard Description
gloddy_finis_IM Glossy A-1, A-2, A-3 The mold is smoothed and then polished with a diamond buff, resulting in parts with a mirror-like finish.
Semi-gloss Semi-gloss B-1, B-2, B-3 The mold is smoothed with fine grit sandpaper, resulting in parts with a fine surface finish.
Matte Matte C-1, C-2, C-3 The mold is smoothed using fine stone powder, removing all machining marks.
Textured finish Textured finish D-1, D-2, D-3 The mold is first smoothed with fine stone powder and then sandblasted, resulting in a textured surface.
As-machined finish As-machined finish   The mold is finished to the machinist's discretion. Tool marks may be visible.

Injection molding design guidelines

The table below summarizes the recommended and technically feasible values for the most common features encountered in injection molding.
  Feature Recommended Description
IM101-rules-wall_thickness Wall thickness Thickness: 1 mm and 3 mm To avoid warping and sinking, parts should be designed with the smallest possible and constant wall thickness.
IM101-rules-smooth_transitions Smooth transitions 3 × wall thickness difference If wall thickness cannot be avoided, use a chamfer or fillet to make the transition as smooth as possible.
IM101-rules-rounded_edges Rounded edges Internal edges: > 0.5 × wall thickness
External edges: internal fillet + wall thickness
Add a fillet with a radius that is as large as possible to all internal and external edges.
IM101-rules_draft_angle Draft angle For parts taller than 50 mm: increase the draft by 1° for every 25 mm For parts with a textured finish: increase the draft by an extra 1°-2°    Add a draft to all vertical walls to make the ejection of the part easier and avoid drag marks.

Free moldability analysis within hours


Yiannopoulos provides one-stop rapid prototyping services & low volume injection molding manufacturing services. With years of manufacturing experience, our experts offer the best solution for all your rapid manufacturing needs.


   Phone: +86-752-6682869
   Mobile: +86-13352636504
   Email:
   LongGang Village, LongXi Town, BoLuo County,HuiZhou City, GuangDong Province, China


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