It is important to note that ASTM standards are copyrighted documents. While you may find unofficial summaries or older versions on various file-sharing sites, relying on unauthorized copies can be risky for professional compliance, as they may be missing critical updates or errata.
Official Sources: The safest and most reliable way to obtain the ASTM D618-21 PDF is through the ASTM International website (astm.org).
Engineers often confuse ASTM D618 with ISO 291. The key difference is philosophical:
If your customer requires ASTM compliance, a generic ISO 291 document will not suffice. You must reference an ASTM D618-21 pdf in your quality management system.
Report: ASTM D618-21 Standard Practice for Conditioning Plastics for Testing 1. Executive Summary
ASTM D618-21 ("Standard Practice for Conditioning Plastics for Testing") is the critical industry standard for preparing plastic specimens prior to physical, mechanical, or electrical testing. It defines precise procedures for controlling temperature and relative humidity (RH) to ensure reliable, reproducible test results and to eliminate variability caused by previous environmental exposure. This standard ensures that materials are brought into a known, consistent state before testing, often allowing for comparisons between laboratories. 2. Scope and Purpose
Purpose: To standardize the atmosphere (temperature and humidity) to which plastics are subjected before and during testing. astm d618-21 pdf
Applicability: Applies to most plastics, including molding materials, sheets, and finished products, prior to tests such as tensile strength, flexural properties, and dielectric strength.
Equilibrium: While often intended to achieve equilibrium, the procedures focus on providing a consistent conditioning baseline, acknowledging that full equilibrium might take 20–100+ days. 3. Key Conditioning Procedures
ASTM D618-21 defines several specific procedures (Procedures A through E) to simulate various service environments: Procedure A (Standard Lab Atmosphere): Condition at Relative Humidity. Duration: 40 hours for thickness ≤is less than or equal to 7 mm, 88 hours for > 7 mm. Procedure B (Oven Conditioning): Conditioning in an oven at for 48 hours, followed by cooling in a desiccator.
Procedure C (Water Immersion): Immersion in distilled water at for 48 hours, followed by cooling in water to Procedure D (High Humidity): Conditioning at
Alternative Specifications: If a material specification differs from this practice (e.g., in ASTM D4000), the material specification takes precedence. 4. Significance and Use
Reproducibility: Eliminates the impact of previous exposure history. It is important to note that ASTM standards
Service Prediction: Subjects material to specific humidity/temperature conditions to predict long-term performance.
Quality Control: Crucial for standardizing material performance during QC checks.
International Alignment: Comparable to ISO 291, though ASTM D618-21 is recognized for being more adaptable and precise. 5. Technical Requirements Temperature: Standard laboratory temperature is Humidity: Standard laboratory relative humidity is
Time: Specified periods (e.g., 40h or 88h) depend heavily on the thickness of the material.
Safety: The standard notes it does not address all safety concerns associated with its use, particularly when using high-temperature ovens or high humidity chambers. 6. Accessing the Document
The official ASTM D618-21 PDF can be purchased and downloaded through the ASTM International Website or ANSI Webstore. If your customer requires ASTM compliance, a generic
Disclaimer: This report is a summary for informational purposes based on 2026 data. Always refer to the official, current version of the standard.
Specific conditioning requirements for a certain plastic type (e.g., Nylon vs. PE)?
Procedures for creating an accurate summary of the 2025 revision discussions? Let me know what details you need to complete your report.
Standard Practice for Conditioning Plastics for Testing - ASTM
Failing to condition specimens can lead to:
One well-known case involved nylon gears that cracked in the field because the supplier tested them as-molded (dry-as-molded) rather than conditioning them to equilibrium per D618-21. The dry-as-molded strength was 30% higher than the conditioned strength—a disastrous overestimation.
Once you have your ASTM D618-21 pdf, follow this 5-step implementation checklist: