Mould Precision Co., Ltd. knows well of SPI Mold Specifications, MP design and maufacturing molds range from class 101 mold to class 105 mold.

SPI Mold Specifications


  • 1. Customer to approve mold design prior to start of construction.
  • 2. All molds, with the exception of prototype, to have adequate channels for temperature control.
  • 3. Wherever feasible, all details should be marked with steel type and Rockwell hardness approximately .005 deep.
  • 4. Customer name, part number, and mold number should be steel stamped on mold.
  • 5. All molds should have eyebolt holes on the top side. There should be one above and one below the parting line to facilitate mold removal, if required, in halves.


  • Cycles: One million or more.
  • Description: Built for extremely high production. This is the highest priced mold and is made with only the highest quality materials.
  • Detailed mold design required.

  • Mold base to be minimum hardness of 28 R/C.
  • Molding surfaces (cavities and cores) must be hardened to a minimum of 48 R/C 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 mold, 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 molds.


  • Cycles: Not exceeding one million
  • Description: Medium to high production mold, good for abrasive materials and/or parts requiring close tolerances. This is a high quality, fairly high priced mold.
  • Detailed mold design required.

  • Mold base to be minimum hardness of 28 R/C.
  • Molding surfaces should be hardened to a 48 R/C 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 molds.
  • 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:
    • a. Guided Ejection
    • b. Slide Wear Plates
    • c. Corrosive Resistant Temperature Control Channels
    • d. Plated Cavities


  • *Cycles: Under 500,000
  • Description: Medium production mold. This is a very popular mold for low to medium production needs. Most common price range.
  • Detailed mold design recommended.
  • Mold base must be minimum hardness of 8 R/C.
  • Cavity and cores must be 28 R/C or higher.
  • All other extras are optional.


  • *Cycles: Under 100,000
  • DDescription: Low production mold. Used only for limited production preferably with non-abrasive materials. Low to moderate price range.
  • Detailed mold design recommended.
  • Mold base can be of mild steel or aluminum.
  • Cavities can be of aluminum, mild steel or any other agreed upon metal.


  • Cycles: Not exceeding 500
  • Description: Prototype only. This mold will be constructed in the least expensive manner possible to produce a very limited quantity of prototype parts. It may be constructed from cast metal or epoxy or any other material offering sufficient strength to produce minimum prototype pieces.