ASTM D647 is a withdrawn ASTM practice that addressed how to design molds used to produce standardized plastic test specimens. It focused on mold design concepts and example layouts intended to improve specimen geometry consistency for subsequent mechanical and physical property testing.
If you are updating an older qualification plan or you have a legacy drawing that references ASTM D647, it is often important to map that requirement to the current specimen-preparation practices used today. For help aligning a legacy citation to a modern molding and testing workflow, you can contact our team.
ASTM D647-88a — Practice for Design of Molds for Test Specimens of Plastic Molding Materials (Withdrawn 1994)
ASTM D647 was published as a practice describing mold designs used to prepare common plastic test specimen shapes. While D647 is withdrawn, it still appears in some legacy material specifications, internal procedures, and older test reports.
This document is best understood as specimen-preparation guidance. It does not replace the product/property test methods (for example, tensile or impact methods) that are performed on the molded specimens.
Quick Definition
In one line: A withdrawn ASTM practice that provided example mold designs for producing bar, disk, and tensile test specimens from plastic materials (via compression, transfer, and injection molding routes).
Document type: Practice (withdrawn).
What This Standard Covers
ASTM D647 covered mold design for plastic test specimens and showed example designs for multiple molding approaches.
What it focused on: Standardized mold geometry concepts intended to promote specimen uniformity, recognizing that processing conditions can still cause property differences even when a mold is standardized.
Molding approaches included: Compression mold designs, a transfer mold design (commonly associated with thermosetting materials), and an injection mold design (used for thermoplastic or thermosetting materials).
Why This Standard Matters in Testing
For many plastics, test results can be strongly influenced by specimen preparation. Mold layout, cavity design, and the broader molding setup can affect internal structure, residual stress, and repeatability.
ASTM D647’s value in a modern lab environment is usually tied to traceability: it helps explain what an older procedure meant when it specified a particular mold style for preparing test bars, disks, or tensile specimens.
Common Materials, Product Types, or Applications Covered
This practice addressed molds for plastic materials used to produce standard test specimen shapes. It was oriented around specimen-making workflows rather than any one end product category.
Common specimen forms referenced: Bar specimens, disk specimens, and tensile specimens used with separate ASTM property test methods.
Common Test or Verification Workflow
ASTM D647 fits into the front end of a plastics testing workflow where molded specimens are produced first, then tested under the relevant property methods.
Typical workflow pattern:
- Select the molding route appropriate to the material (compression, transfer, or injection molding).
- Produce standardized specimen geometries using a mold design aligned with the intended test method(s).
- Follow the applicable material specification or supplier guidance for molding conditions when needed.
- Perform the required property tests on the molded specimens using the cited test methods.
Equipment Commonly Used for This Standard
Because ASTM D647 is a mold-design practice, it connects more directly to specimen preparation equipment than to a single test machine. The downstream test equipment depends on which property methods the molded specimens will be used for.
Common equipment families:
- Compression molding press and matched mold sets (for bar/disk/tensile specimen molds intended for compression molding).
- Transfer molding equipment and transfer molds (commonly associated with thermosetting compound specimen preparation).
- Injection molding machine and multi-cavity mold tooling (ASTM D647 included an example four-cavity injection mold arrangement intended for use with many injection molding machines of 55 g or greater capacity, adaptable to common mold base sizes).
- Ancillary molding controls as needed for stable processing (for example temperature control and process monitoring), aligned with the material specification or supplier guidance.
If you are sourcing specimen mold tooling or aligning specimen dimensions to the test methods in your scope, you can request pricing for a setup matched to your molding route and specimen types.
How to Read This Designation or Revision
ASTM D647 follows ASTM’s designation style where the letter/number identify the standard and the suffix and year markers identify the version.
Common citation pattern seen in legacy documents: D 647-88a (for example, an “a” suffix can indicate a revision within the same year).
Revision sensitivity: For legacy standards like D647, mold drawings and cavity layouts can vary by edition. When a contract, internal procedure, or customer specification cites ASTM D647, it is best to match the exact cited edition before treating any dimensions or mold details as requirements.
Related Standards, Methods, or Frameworks
ASTM D647 is withdrawn and is commonly encountered as a legacy reference tied to plastics specimen preparation and property testing.
Commonly associated ASTM areas: Plastics specimen molding practices (for example injection molding and compression molding specimen preparation practices) and downstream plastics property methods (for example tensile or impact test methods) that depend on consistent molded specimen geometry.
Talk with Us About Legacy ASTM D647 Citations
If your procedure references ASTM D647 but your lab runs modern specimen-preparation practices, we can help translate the intent into a practical plan for specimen molding, documentation, and equipment scope. To discuss your material type and specimen forms, talk with our team.