Physical Address
304 North Cardinal St.
Dorchester Center, MA 02124
D3965-21 – Standard Test Method Technical Guide
📐 Scope and Classification System
ASTM D3965-21 establishes a classification system for rigid ABS materials used in pipe and fittings. It applies only to virgin ABS polymers and blends, excluding reprocessed, regrind, or recycled materials. The classification is based on five key properties: Izod impact strength at room temperature, Izod impact strength at low temperature, deflection temperature under load, tensile stress at yield point, and modulus of elasticity in tension. These properties are used to assign a cell class designation for material identification per Table 1. Values stated in SI units are standard; this standard differs in technical content from ISO 7245-1984.
Warning: This standard does not address requirements for finished pipe or fittings; consult the applicable ASTM product standard for such requirements.
⚙️ Testing Methods and Property Requirements
Materials are tested per ASTM D256 for Izod impact, ASTM D638 for tensile properties, and ASTM D648 for deflection temperature. Conditioning of specimens follows ASTM D618. The table below provides example cell class values for ABS materials based on typical property ranges.
| 🟦 Cell Class | 📏 Izod Impact RT (J/m) | 📐 Izod Impact Low Temp (J/m) | 🎯 Deflection Temp (°C) | ⚡ Tensile Stress (MPa) | 📊 Elastic Modulus (GPa) |
|---|---|---|---|---|---|
| Class 1 | 200 | 150 | 85 | 40 | 2.0 |
| Class 2 | 250 | 180 | 90 | 45 | 2.2 |
| Class 3 | 300 | 200 | 95 | 50 | 2.5 |
These values are illustrative; the standard contains a complete set of cell class requirements in Table 1. In-house rework by the original ABS manufacturer is permitted if the material meets the physical and mechanical properties specified in its callout.
Tip: Always refer to the current edition of D3965 for official cell class values and tolerances.
❓ Frequently Asked Questions
🔍 What materials does D3965-21 cover?
It covers virgin ABS polymers and blends for extrusion of pipe and molding of fittings, excluding recycled materials.
💡 What properties are used for classification?
The five properties are Izod impact at room and low temperature, deflection temperature under load, tensile stress at yield, and elastic modulus.
⚡ Can rework material be used in production?
Yes, in-house rework by the original manufacturer is allowed if the final product meets the property requirements per Table 1.
📌 Is this standard intended for material selection?
No, it is designed for classification and specification. Material selection requires expertise in plastics engineering and consideration of design and environmental factors.