CLASSIFICATIONS OF INJECTION MOLDS FOR THERMOPLASTIC MATERIALS

TO: THOSE INVOLVED IN THE PURCHASING OR THE
MANUFACTURING OF THERMOPLASTIC
INJECTION MOLDS

CLASSIFICATION OF INJECTION MOLDS

GENERAL NOTES


A) The following classifications are guidelines to be used
in obtaining quotations for a uniform type of tooling and
placing orders for the same. It is our desire through these
classifications to help even out the inequities in the
plastic molding quote system and eliminate the customer
who gets less than he feels he paid for.

B) It is highly recommended that tooling drawings be
obtained before construction is started on any injection
mold. Some parts may seem simple enough to not warrant a
tool design but in the event of any tooling damage, a
drawing showing sizes and steel types can easily pay for
itself.

C) These specifications refer to molds for standard
thermoplastic materials and products generally not
exceeding thirty square inches of projected surface area.
Those parts would normally be run in machines with clamp
ratings of 400 tons and less. Larger molds quite often
have different requirements and we hope to establish
standards for these larger tools in the near future.

D) These classifications are for tooling 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.

E) Mold life, because of variations in materials and molding
conditions, cannot be guaranteed. We will attempt to
give you approximate cycles for each type of mold
discounting wear caused by material abrasion.

F) 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 (provided he
originally built and has maintained possession of the
tool). Maintenance caused by excessive wear should be
borne by the customer. Example of this would be: worn
gates, worn cavity and/or core caused by gate "jetting"
with abrasive materials, flashing down and around ejector
pins or sleeves caused by excessive number of cycles, re-
plating or re-texturing of cores and/or cavities worn by
abrasive materials. The specter of mold rework costs
should be closely considered when deciding which
classification of tooling you require.

CLASSIFICATIONS OF INJECTION MOLDS

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


CLASS I MOLD

CYCLES: One million or more

DESCRIPTION: Built for extremely high production. This is
the highest price tooling and is made with only the highest
quality materials.


CLASS II MOLD

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 tool.


CLASS III MOLD

CYCLES: Under 50,000

DESCRIPTION: Medium production mold, this is a very popular
mold for low to medium production needs. Most common price
range.

PURCHASING AGENTS SECTION

CLASS IV MOLD

CYCLES: Under 10,000

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


CLASS V MOLD

CYCLES: Not exceeding 500

DESCRIPTION: Proto-type only. This tooling will be
constructed in the least expensive manner possible to produce
a very limited quality of proto-type.



CLASS I INSERT**

CYCLES: Approximately 250,000

DESCRIPTION: Top quality materials for medium to high
production requirements.


CLASS II INSERT**

CYCLES: Under 50,000

DESCRIPTION: Similar to Class III Mold. Most commonly used
insert. Low to medium production.


CLASS III 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.

** When buying inserts, the customer buys only the insert.
The 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 the product produced by another
vendor without having to purchase a mold base.

TOOLING INFORMATION SECTION

CLASSIFICATIONS OF INJECTION MOLDS

NOTE: In this section we will attempt to detail the
materials and the processes to be used in producing
the various classifications of tooling.


GENERAL SPECIFICATION

1. Customer to approve mold design for Class I, II, and III
Molds and Class I and II Inserts prior to start of
construction.

2. All tools, with the exception of proto-type, 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 tool number should be
steel stamped on all molds and/or inserts.

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.

6. The ejector plate ends should be painted high visibility
yellow or orange to comply with recent OSHA standards.

7. All ejector pins should be nitrided or hardened.

8. Tie straps should be provided with molds to eliminate
the possibility of damage caused by the tool accidentally
opening.

9. Molds for materials that give off caustic or acetic
fumes should have molding surfaces plated or made of
steel resistant to those gasses.

10. In multi-cavity molds, all identical cavities must be
individually identified if possible.

CLASSIFICATIONS OF INJECTION MOLDS

CLASS I MOLD

1. Detailed tool design required. Should be approved by
customer prior to start of construction.

2. Mold base to be 300 BHN (equivalent to DME #3 steel).

3. Molding surfaces (cavities and cores) must be tool steel
hardened to at least 48 R/C. All other details, such
as; slides, heel blocks, gibs, wedge blocks, etc. should
also be of hardened tool steels.

4. Ejection must be guided.

5. Slides must have wear plates.

6. Temperature control channels to be in cavities, cores
and side cores whenever possible.

7. Cavities should be plated for protection unless
stainless steel is used.

8. Hardened runner plates are required except for hot or
insulated runner molds.

9. Electroless nickel plating of all water channels is
recommended. This greatly inhibits the chance of rust
and makes it easy to clear sediment from plugged lines.

10. Eyebolts are required on all four sides above and below
parting line.

11. Taper locks or similar interlocking devices are required
on molds where extremely close tolerances must be
maintained.

12. It is recommended that the entire mold base be
electroless nickel plated, parkerized, or in some similar
way protected from rust and corrosion.


CLASS II MOLD

1. Detailed tool design required. Should be approved by
customer prior to start of construction.

2. Mold base to 300 BHN (equivalent to DME #2 or better
steel).

3. Molding surfaces (cavities and cores) must be tool steel
hardened to at least 48 R/C. All other functional
details should be made and heat treated likewise.

4. Temperature control channels to be directly in the
cavities, cores, and side cores wherever possible.

5. Taper lock or other similar interlocking devices are
required on molds where extremely close tolerances must
be maintained.

6. The following items may or may not be required depending
on the ultimate production quantities anticipated. It is
recommended that those items desired be checked and made
a firm requirement for quoting purposes:

a. Guided Ejection
b. Slide Wear Plates
c. Plated Temperature Control Channels
d. Plated Cavities
e. Hardened Runner Pads


CLASS III MOLD

1. Detailed tool design recommended.

2. Cavity back up plates must be 300 BHN (equivalent to DME
#2 or better steel). Remainder of mold base may be mild
steel.

3. Cavity and cores must be pre-hardened steel or better.

4. All other extras are optional.


CLASS IV MOLD

1. Tool design recommended.

2. Mold base can be of mild steel or aluminum.

3. Cavities can be of aluminum, mild or any other agreed
upon metal.

4. All other extras are optional.


CLASS V MOLD

1. May be constructed from cast metal or epoxy or any other
material offering sufficient strength to produce 500
injection molded pieces.


CLASS I INSERT

1. Detailed tool design required. Should be approved by
customer prior to start of construction.

2. Insert to be at least 300 BHN (equivalent to DME #3
steel).

3. All molding and/or functional details are to be made of
tool steel hardened to at least 48 R/C.

4. Slides must have wear plates.

5. Temperature control channels to be in cavities and cores
wherever possible.

6. Molding details should be plated for protection unless
stainless steel is used.

7. Electroless nickel plating of all water channels is
recommended.

8. Taper locks or other similar interlocking devices are
required on inserts where extremely tight tolerances
must be maintained.

9. Inserts must have leader pins and bushings or some
similar guidance system.

10. It is recommended that the entire insert be electroless
nickel plated, parkerized or in some similar way
protected from rust or corrosion.


CLASS II INSERT

1. Detailed tool design required. Should be approved by
customer prior to start of production.

2. Insert retainer to be at least 300 BHN.

3. Cavities and cores must be of pro-hardened or fully
hardened steels.

4. All other extras are optional.


CLASS III INSERT

1. Can be constructed from aluminum, cast metal, cast epoxy
or any material with sufficient strength to produce at
least 500 injection molded pieces.