SPE Mold Specs

The tool specification guidelines listed below, were developed by the U.S. Society of Plastic Engineers (SPE), with the intent of having a simplified definition of the type of injection tool for thermoplastics required for a set production need.

These guidelines are intended to be just a reference that frequently further evolve, on a project by project basis or depending on the customer, so that they better reflect what is required of a specific tool.

The different classifications will dictate differences in tool design, construction, materials, and components.

  1. Class 101:  Extremely High Volume
    Extremely high volume production injection tools built for lifetime cycles exceeding one million.
  2. Class 102: High Volume
    Medium to high volume production injection tools built for lifetime cycles not to exceed one million.
  3. Class 103: Medium Volume
    Medium volume production injection tools built for lifetime cycles not to exceed 500,000.
  4. Class 104: Low Volume
    Low volume production injection tools built for lifetime cycles not to exceed 100,000.
  5. Class 105: Prototype Only
    Prototype only tools are built for lifetime cycles not to exceed 500.
Tool Classification Category Extremely High Volume High Volume Medium Volume Low Volume Prototype Only
Runnerless Design (If Part Allows) X
Stainless Steel or, Electroless Nickel Plated Tool Base X
Spare Parts for Tooling X      X
Stainless Steel or Electroless Nickel Plated Cooling Plates X      X
Automatic injection Cycles & Part De-gating X X X
Full Detailed Tool Design X X X
Heat Treated Cavity & Core Inserts X X
Parting Line Interlocks X X X
Guided Ejection X X X
Wear Plates on all Slides X X X
Automatic Side Actions X X X
Spring Loaded or Mechanically Operated KO System X X X X
Cycle Counter X X X X
Pre-Hardened Cavity & Core Inserts       X X X
Aluminum Cavity & Core Inserts or Aluminum Mold        X

 

Class 101 Tool – Cycles: One million or more

Description: Built for extremely high production. This is the highest priced tool and is made with only the highest quality materials.

  • Detailed tool design required.
  • Tool structure components to have a minimum hardness of 28 Rc.
  • Cavity and cores must be hardened to a minimum of 48 Rc range. All other details, such as sub-inserts, slides, heel blocks, gibs, wedge blocks, lifters, etc. should also be of hardened tool steels.
  • Ejection should be guided.
  • Slides must have wear plates.
  • Temperature control provisions to be in cavities, cores and slide cores wherever possible.
  • Over the life of a tool, corrosion in the cooling channels decreases cooling efficiency thus degrading part quality and increasing cycle time. It is therefore recommended that plates or inserts containing cooling channels be of a corrosive resistant material or treated to prevent corrosion.
  • Parting line locks are required on all tools.

Class 102 Tool – Cycles: Not exceeding one million

Description: Medium to high production tool, good for abrasive materials and/or parts requiring close tolerances. This is a high quality, fairly high priced tool.

  • Detailed tool design required.
  • Tool structure components to have a minimum hardness of 28 Rc.
  • Cavities and cores should be hardened to a minimum of 48 Rc range. All other functional details should be made and heat treated.
  • Temperature control provisions to be directly in the cavities, cores, and slide cores wherever possible.
  • Parting line locks are recommended for all tools.
  • The following items may or may not be required depending on the ultimate production quantities anticipated. It is recommended that those items desired be made a firm requirement for quoting purposes.
    • Corrosive Resistant Temperature Control Channels
    • Plated Cavities

Class 103 Tool – Cycles: Under 500,000

Description: Medium production tool.

  • Detailed tool design recommended.
  • Tool structure components must have a minimum hardness of 18 Rc.
  • Cavity and cores must be 28 Rc or higher.
  • All other extras are optional.

Class 104 Tool – Cycles: Under 100,000

Description: Low production tool. Used only for limited production preferably with non-abrasive materials. Low to moderate price range.

  • Tool design recommended.
  • Tool structure components can be of mild steel or aluminum.
  • Cavities can be of aluminum, mild steel or any other agreed upon metal.

Class 105 Tool – Cycles: Not exceeding 500

Description: Prototype only. Tool to be constructed in the least expensive manner possible to produce a very limited quantity of prototype parts.

  • All components are optional

Notes and Comments:

  1. Class 101: Extremely High Volume, Class 102: High Volume and Class 103: Medium Volume production tools, if at all possible, should be designed and manufactured to run fully automatic cycles with automatic ejection.    Class 101, Class 102 and Class 103 tools should be designed to best accommodate the selected method of automated part removal from the mold.
  2. All tools, with the exception of C105, should have adequate cooling for temperature control.
  3. Wherever feasible, all components should be marked with steel type and Rockwell hardness approximately.
  4. All tools should have transport eyebolt holes on the top side. With the exception of Class 105, transit eyebolt holes should be machined in all plates.
  5. Customer should approve tool design prior to the start of manufacturing.