• Injection Molding

Injection Molding Processes

Make the move from prototyping to on-demand manufacturing for affordable, high-quality molded parts within days. This is when your prototyping tool is proof of concept once you shift to an on-demand manufacturing tool. Working with a single supplier that provides free design consultation services also massively speeds up the manufacturing process, allowing for greater supply chain flexibility, more consistent parts, and making qualification a breeze.

Consistency and Quality

We combine scientific (or decoupled) molding techniques, which optimize and lock in processing parameters to ensure part consistency—with extra attention paid to critical-to-quality dimensions using our proprietary automated CMM process.

Know Your Injection Molding Raw Materials

Virtually any type of thermoforming resin can be used in the injection molding process. There are thousands of different types of materials to choose from to enable you to achieve the performance, color, and quality that you need for your design. Check out our sheet of frequently used materials.

Injection Molding Capabilities

We will start with a computer model of the part that you provide or that we create using Solidworks, then program our CNC machines using Camworks CNC software or at the machine using the CNC machine’s built-in conversational programming capabilities.

Service Details

Lead Time

Starts at 10 business days, including 24-hour quote responses with design-for-manufacturing (DFM) feedback

Production Options

Domestic and international


Most plastics, including custom sourcing and matching; see materials list below

Machines Available

Single, multi-cavity, and family molds; 50 to 1,100+ press tonnage; side actions including hand-loaded cores

Inspection and Certification Options

Includes FAI and PPAP. ISO 9001, AS9100, ISO 13485, UL, ITAR, and ISO 7 and 8 Medical Clean Room molding.

Tool Ownership

Customer-owned with mold maintenance

Mold Cavity Tolerances

+/- 0.005″ when machining the mold and an additional +/- 0.002″ per inch when calculating for shrink rate

Part to Part Repeatability

+/- 0.004″ or less

Critical Feature Tolerances

Tighter tolerances can be requested and may increase the cost of tooling because of additional sampling and grooming. Xometry will mill to a steel-safe condition on critical features.

Available Mold Types

Steel and aluminum; Production grades range from Class 105, a prototype mold, to Class 101, an extremely high production mold. Xometry typically produces Class 104, 103, and 102 tools.

How we make is as important as what we make. Putting people first. Opening doors through innovation

Plastic Injection Molding Materials

Rigid And Flexible Resins

ABS | Acrylonitrile Butadiene Styrene

ASA | Acrylonitrile Styrene Acrylate

CA | Cellulose Acetate

COPO | Copolyester

HDPE | High-Density Polyethylene

LCP | Liquid Crystal Polymer

LDPE | Low-Density Polyethylene

PA 6 | Polyamide 6, Nylon 6

PA 6/6 | Polyamide 6/6, Nylon 6/6

PARA | Polyaryl Amide

PBT | Polybutylene Terephthalate, Valox

PBT-PET | Polybutylene Terephthalate-Polyethylene Terephthalate

PC | Polycarbonate

Elastomers and Synthetic Rubbers for Molding

Elastomers and Rubber-Like Materials

EPDM | Ethylene Propylene Diene Monomer Rubber, Viton

MPR | Melt Processable Rubber

POE | Polyolefin Elastomer

PVC | Polyvinyl Chloride (Shore A)

Plastic Injection Molding Materials

Feature Tip


Reduce undercuts, which will increase the complexity and cost of the tool ejection mechanisms, by adding in pass-thru coring.

Wall Thickness

Prevent wall sink and voids by maintaining an even wall thickness. Thinner walls reduce cycle time and reduce costs.


Ensure parts are designed with a minimum draft angle of 0.5°, or up to 5°, for faces with medium textures.


Ribs should be 40-60% the thickness of outer walls and should still maintain draft.


Bosses should be designed at a depth of 30% the wall thickness and with a 30% edge groove. Attach them to side walls or ribs for structural integrity.

How Injection Molding Works

Plastic injection molding is by far the most common way to produce large volumes of finished plastic parts for every kind of commercial and industrial use. In this process, melted liquid resin is injected under high pressure into the cavity of a metal die and then rapidly cooled, forming a solid shape. A single cycle to make a finished part may take anywhere from a few seconds to minutes depending on part complexity, size, and design.

Plastic Injection Molding Tolerances

All plastics expand and contract to a certain extent under the influence of heat and moisture. Our manufacturing tolerance guide gives you general information on the shrinkage characteristics of the most common resin types to help guide your design decisions.

Related Projects