New Benchtop Plastic Injection Molding Machines

All our New machines come with a 1 year limited warranty *

The Proto-Ject line of benchtop injection molding machines is Manning Innovations' flagship product. Sometimes referred to as tabletop or desktop injection molders, these machines are capable of producing surprisingly large parts for their size and weight. They easily outclass any other benchtop machine on the market today in terms of....


  • Ease of use
  • Mobility
  • Injection volume
  • Injection force
  • Clamp force
  • Part size
  • Power requirements
  • Affordability


Don't be fooled with the empty promises of the tiny "toy" benchtop molding machines or the allure of 3D printers flooding the market today. Making a real plastic part requires a real plastic molding machine. The Proto-Ject machines were designed from the ground up to be a workhorse for...


  • Manufacturers needing to make dozens, hundreds or even thousands of real working plastic parts fast and affordably
  • Product R&D and prototyping
  • Quality Labs

In production since 2011, these machines are serving these very markets all across the US. Currently available in two sizes and various configurations, we are certain that one of the Proto-Ject machines is right for your needs.

Proto-Ject 150HP (High Pressure)

The 150HP has a max shot size of 1.5 ounces and has the highest injection pressure of any of our machines making it best suited for higher molecular weight plastics and thus can work with the broadest range of materials of any of the Proto-Ject machines. We have even used this machine successfully with some extrusion grade materials. It is our most popular machine due to its versatility. Powered by standard single phase power and compressed air, it is lightweight, clean and can work almost anywhere from large manufacturing floors to laboratories to small shops and garages. Its aluminum frame makes it easy to move from place to place with only a couple of people and no specialized lift equipment. This also allows the machine (in parting line configuration) to ship with standard carriers (UPS or FedEx) instead of the more cumbersome and expensive truck freight required of heavier machines. The 150HP is now also available with the AST (Air Saving Technology) option which reduces the air consumption by up to 70% over the standard model, allowing the use of a single phase 110-120VAC compressor in even high production rate applications (see FAQ section for more details on compressor sizing and suggestions). The 150 is available in two injection configurations (parting line and through mold side) and with various clamp methods and tonnage. Specifications vary per configuration but typically include...

  • Shot size - 1.5 oz max (suitable for parts of up to 3/4 oz, see FAQs for more details on this recommendation)
  • Injection pressure - 9300psi at 145psi air input pressure
  • Clamp tonnage - 10, 20 and 40 ton (depending upon clamp selected)
  • Max operating temperature - 800°F
  • Mold size (varies per configuration)
  • Electrical Power - 110-120 VAC single phase
  • Compressed air requirement - 145psi max (flow rates vary per configuration)
  • Machine weight (varies per configuration, but all models can typically be lifted and carried by two people)

Proto-Ject 300

The Proto-Ject 300 has similar size and weight specifications to the 150HP, except it has a larger injection volume but with a lower max injection pressure. It is best suited for plastics with low to medium-high molecular weights, and when working with plastics within this range (most common injection grade plastics), it can handle part sizes up to 1.5 oz (see FAQs to understand shot size vs part size). The 300 is available in two injection configurations (parting line and through mold side) . However, the "through the side injection" version, does require shipment via truck freight. Available with AST (Air Saving Technology) which can reduce the air consumption as much as 70%, the 300 still generally requires a 220-240VAC single phase compressor for operating frequent cycles, since it will typically require higher air pressure than the 150HP for a given plastic which will likely result in an overall higher CFM requirement (see FAQ for compressor selection and recommendations). In lab use or R&D work, or in lower volume production or with plastics that allow lower injection pressures a smaller air compressor may still prove adequate. Specifications include...

  • Shot size - 3.0 oz max (suitable for parts of up to 1.5 oz, see FAQs for more details)
  • Injection pressure - 5200psi at 145psi air input pressure
  • Clamp tonnage - 10, 20 and 40 ton (depending upon clamp selected)
  • Max operating temperature - 800°F
  • Mold size (varies per configuration)
  • Electrical Power - 110-120 VAC single phase
  • Compressed air requirement - 145psi max (flow rates vary per configuration)
  • Machine weight (varies per configuration, but all models can typically be lifted and carried by two people)
*Limited 1 Year Warranty: Manning Innovations (seller) warrants to the original purchaser (buyer) of any of our new machines that they shall be free from defects in materials and workmanship for a period of 1 year from the date of purchase. This warranty does not apply to damage due to misuse, abuse, negligence, accidents, repairs, modifications, wear and tear or the lack of proper maintenance. Machines must be returned to Manning Innovations with shipping cost prepaid and properly packaged to prevent damage (damage due to improper shipping is not covered under this warranty and will not be the responsibility of Manning Innovations and may void any rights to this warranty by the buyer). Documents showing proof and date of purchase as well as a description of the the defect must accompany the machine. Buyer must contact the seller in writing (email) to obtain a return authorization before returning any machine or part thereof. Once received, if we verify the defect falls within the scope of our warranty, we shall repair the machine (or part) and return at our (seller's) expense. However, if we determine that the claim is invalid, return shipping will be at the buyer's expense. In the event that we cannot readily repair or replace the machine, we may elect to return the original purchase price of the machine less any shipping charges incurred by the buyer at the time of sale or any time thereafter. Manning Innovations shall in no event be held liable for death, injuries to persons or property, or for incidental, contingent, special or consequential damages arising from the use of any of our machines or products. This warranty gives the buyer specific legal rights and my not express other rights the buyer may have which may vary among locations. THIS WARRANTY IS EXPRESSLY IN LIEU OF ALL OTHER WARRANTIES (EXPRESSED OR IMPLIED) INCLUDING THE WARRANTIES OF MERCHANTABILITY AND FITNESS.