SPI Mold Classification

SPI CLASSIFICATION OF INJECTION MOLDS

The following classifications are guidelines to be used in obtaining quotations and placing orders for a uniform type of molds. It is our desire through these classifications to help even out inequities in the plastics molding quote system and eliminate customer disappointment.

It is strongly recommended that mold drawings be obtained before construction is started on any injection mold. Even though parts may seem simple enough to not warrant a mold design, in the event of mold damage a drawing showing sizes and steel types will pay for itself.

These classifications are for mold specifications only and in no way guarantee workmanship. Workmanship is an individual and intangible thing. It is very important that purchasing agents deal with vendors whose workmanship standards and reliability are well proven.

Mold life, because of variations in part design and molding conditions, cannot be guaranteed. We will attempt to give approximate cycles for each type of mold excluding wear caused by material abrasion, poor mold maintenance and improper molding technique.

Maintenance is not the responsibility of the moldmaker. Normal maintenance such as replacement of broken springs, broken ejector pins, worn rings, or the rework of nicks and scratches should be borne by the molder. The spectre of mold rework costs should be closely considered when deciding which classification of mold is required.

This document does not constitute a warranty or guarantee by the Society of Plastics Industry, Inc., or its members for the classifications or specifications set forth herein.

GUIDE FOR PURCHASER

CLASSIFICATIONS OF INJECTION MOLDS UP TO 400 TONS

This section contains a brief synopsis of the various mold classifications. The following section contains detailed descriptions of each mold class. It is our recommendation that this “mold information” sheet be included with each request for quotation.

TYPE 1O1 MOLD
Cycles: One million or more
Description: Built for extremely high production. This is the highest price mold and is made with only the highest quality materials.

TYPE 102 MOLD
Cycles: Not exceeding one million
Description: Medium to high production mold, good for abrasive materials and/or parts requiring tolerances. This is a high quality, fairly high priced mold.

TYPE 103 MOLD
Cycles: Under 500,000
Description: Medium production mold. This is a very popular mold for low to medium production needs. Most common price range.

TYPE 104 MOLD
Cycles: Under 100,000
Description: Low production mold. Used only for limited production preferably with non-abrasive materials. Low to moderate price range.

TYPE 105 MOLD
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 product.

TYPE I UNIT INSERT
Cycles: Approximately 500,000
Description: Top quality materials for medium to high production requirements.

TYPE II UNIT INSERT
Cycles: Under 100,000
Description: Similar to Class III Mold. Most commonly used insert. Low to medium production.

TYPE III UNIT INSERT
Cycles: Less than 500
Description: Similar to Class V Mold. Least expensive insert for very limited quantities. Insert built with the least expensive materials.

Notes to consider:
Cycles are approximate and for comparison only.

When buying inserts, the customer buys only the insert. The unit mold base is owned by the molder. Because of the large variation in insert sizes, it should be kept in mind that it may be impossible to have product produced by another vendor without having to purchase a mold base.

(Important: Refer to the general specifications to complete the details of this section, except for prototype molds.)