SPI mold standard classifications

Intruduction

SPI mold standards classifications were created by the society of plastics industry INC( now it is changed to plastics industry association), which helps both plastic injection mold manufacturer and purchaser have the same understanding of the mold quality and standard.

By specifying the SPI mold standard classifications, you are able to ensure that each supplier is in the same general range for the tooling prices. If your engineering team is experienced enough, then further specifications within the SPI mold classification and beyond will be extremely beneficial to the injection molding supply chain.

Following standards or general guidelines will always be the best practices when getting pricing from multiple sources. This will not only save time to get your quotes back, but it will also remove the headache of “back and forth” with the mold makers requesting changes from what they originally quoted.

General specifications

Customer to provide a solid model (C.A.D.) of the part, a 2d part drawing with surface finish and tolerance requirements and the material to be used.
Customer to approve the mold design before mold manufacture.
All molds with exception of prototype mold should have adequate channels for temperature control.
Wherever feasible, all details should be marked with steel type and Rockwell hardness.
The customer name, part number, and mold number should be stamped on the mold base.
All mold plates and large components should have adequate eyebolt holes for easy handing.

Class 101 Mold

Cycles: One Million or more
Description: Built for extremely high production. This is the most expensive class of mold and uses the highest quality materials. This mold needs to run fully automatic.

Detailed tool design required.
Tool structure components to have a minimum hardness of 28 HRC.
Cavity and cores must be hardened to a minimum of 48 HRC 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 the 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 Mold

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 HRC.
• Cavities and cores should be hardened to a minimum of 48 HRC 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 to be made a firm requirement for quoting purposes.
a. Guided ejection
b. Slider wear plates
c. Corrosive Resistant Temperature Control Channels
d. Plated Cavities

Class 103 Mold

Cycles: Under 500,000
Description: Medium production tool. This is a very popular mold for low to medium production needs. Most common price range.
• Detailed tool design recommended.
• Tool structure components must have a minimum hardness of 18 HRC.
• Cavity and cores must be 28 HRC or higher.
• All other extras are optional.

Class 104 Mold

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 Mold

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. It may be constructed from cast metal or epoxy or any other material offering sufficient strength to produce minimum prototype pieces.

All components are optional