Insert Molding

Pilot runs, low volume production, bridge tooling

Insert molding is a great way to combine metal and plastics into one single part. It allows plastic to bond to inserts that go inside a mold cavity, helping you to create better parts.

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Advantages of Insert Molding

Durability

Metal inserts will guarantee the function of threads and mitigate wear and tear over the part’s life.

Strength

Because it’s a “one-shot” process, insert molding can produce stronger parts than overmolding and other processes.

Part Production

Insert molding is great for creating prototypes and production parts.

Insert Molding Materials

Available rigid plastic varieties:

  • ABS
  • Acetal POM [Delrin]
  • Acrylic (PMMA)
  • High-Density Polyethylene (HDPE)
  • Nylon 6
  • Nylon 6/6
  • PBT
  • PC-PBT (Xenoy)
  • PEEK
  • PEI [Ultem]
  • PLA
  • Polycarbonate
  • Polypropylene
  • PPE-PS
  • PSU
  • PVC

Get a quote or learn more about rigid plastics.

Available Flexible Plastic Varieties:

  • Low-Density Polyethylene (LDPE)
  • PC-ABS
  • PET
  • Polyethylene
  • Polystyrene

Get a quote or learn more about flexible plastics.

Available Rubber-Like Plastics

  • TPE
  • TPV

Get a quote or learn more about rubber-like plastics.

Insert Molding Finishes

SPI A-1

Grade #3, 6000 Grit Diamond Buff

SPI A-2

Grade #6 3000 Grit Diamond Buff

SPI A-3

Grade #15 1200 Grit Diamond Buff

SPI B-1

600 Grit Paper. Typical Application: Medium polish parts.

SPI B-2

400 Grit Paper. Typical Application: Medium polish parts.

SPI B-3

20 Grit Paper. Typical Application: Medium- Low polish parts.

SPI C-1

600 Stone. Typical Application: Low polish parts.

SPI C-2

400 Stone. Typical Application: Low polish parts.

SPI C-3

320 Stone. Typical Application: Low polish parts.

SPI D-1

Dry Blast Glass Bead. Typical Application: Satin Finish

SPI D-2

Dry Blast #240 Oxide. Typical Application: Dull Finish

SPI D-3

Dry Blast #24 Oxide. Typical Application: Dull Finish

As Machined

No secondary polishing or grinding. Part will show tooling marks.

Overview: What is Insert Molding?

Benefits of Insert Molding

Done correctly, insert molding can help:

  • Eliminate assembly: You can make parts all at once instead of having to do assembly after the fact.
  • Reduce costs: Insert molding costs more than standard injection molding, but the costs are usually offset by the fact that you no longer need to do post-assembly.
  • Lower the size and weight of the part: A plastic part with a metal insert is generally lighter than an all-metal part.
  • Improve reliability: Metal inserts will guarantee the function of threads and mitigate wear and tear over the part’s life.
  • Improve part strength: Because it’s a “one-shot” process, it can produce stronger parts than overmolding and other processes.

Insert Molding works especially well for parts that have threaded holes. It can also help you create better wheels, pulleys, fan blades, and other similar parts.

What Are the Differences Between Insert Molding and Overmolding?

Both of these processes involve putting two types of materials together to make a part. However overmolding requires two steps: one to create the substrate and one for the overmold that goes on top of it. Insert molding takes only one step, which makes for stronger parts and a more robust structure.

Insert Molding With Xometry

Xometry now offers insert molding as part of its injection molding capabilities. For a free insert molding design review and quote, upload your CAD files here. Our expert team of injection molders will get back to you within 24 hours.

If you want to learn more about our injection molding capabilities, download our design guide here. If injection molding isn’t the best fit for you, you could also try urethane casting or 3D printing.

Industries that use Insert Molding

Injection Molding is used in rapid prototyping and producing pilot and high-volume production parts in a wide range of industries. It is frequently used in industries such as medical, packaging, automotive, consumer electronics, building/construction, and robotics.

Automotive

Consumer Products

Medical Devices

Featured Insert Molding Resources

Overmolding: What You Need to Know

Overmolding: What You Need to Know

Without overmolding, cell phones, steering wheels, kitchen implements and other items you touch every day wouldn’t be the same. We’ve put together a comprehensive introduction to the process so you can determine if overmolding is an ideal choice for your next parts.

What You Need to Know About Insert Molding in 2018

What You Need to Know About Insert Molding in 2018

Ah spring, when a young man’s fancy turns to...insert molding. Insert molding is a great way to combine metal and plastics into one single part. It allows plastic to bond to inserts that go inside a mold cavity, helping you to create better parts.

Learn more about our other capabilities

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