ISO 11125-4:2018

Overview

ISO 11125-4:2018 defines a standardized test method for determining the apparent density of metallic blast-cleaning abrasives using the pycnometer technique. The test verifies the soundness of metallic abrasives: internal shrinkage or hollow particles reduce apparent density and can indicate poor performance or reduced service life. This part of ISO 11125 is part of a coherent set of standards addressing sampling and testing of metallic abrasives for surface preparation.

Key Topics

• Scope and purpose: Establishes a repeatable laboratory method to quantify apparent density and detect structural defects in metallic abrasives.
• Materials and apparatus: Uses distilled or deionized water (ISO 3696, grade 3), an ordinary laboratory pycnometer (Gay-Lussac type, 50 ml capacity with capillary stopper) and a balance accurate to 0.01 g.
• Sampling and preparation: Representative sampling is performed in accordance with ISO 11125-1. Test portions are allowed to stabilise to room temperature before measurement.
• Procedure highlights:
  • Carry out determinations in duplicate.
  • Condition pycnometer, sample and water to room temperature (approx. 1 hour) and minimise handling.
  • Typical test uses approximately 100 g of sample placed in the pycnometer; the pycnometer is filled with water, air bubbles removed and masses recorded.
  • If duplicate results differ by more than 10% (relative to the higher result), repeat the test.
• Expression of results: Apparent density is calculated from the recorded masses and water density at test temperature. Report the mean of two valid determinations to the nearest 100 kg/m3.
• Test report requirements: Include product identification (referencing ISO 11124 where applicable), reference to ISO 11125-4:2018, the test result, any deviations, date and name of the tester.

Applications

This test method is essential for quality control, procurement and application planning where metallic blast-cleaning abrasives are used for steel surface preparation. Practical uses include:

• Verifying batch soundness before use in industrial blast cleaning operations.
• Supporting supplier qualification and incoming goods inspection.
• Informing process engineers about abrasive suitability for production blasting, wear expectations and consistency between batches.

Keywords: apparent density, metallic blast-cleaning abrasives, pycnometer, abrasive soundness, ISO 11125-4.

Related Standards

• ISO 11125-1: Sampling for metallic blast-cleaning abrasives
• ISO 11125-2: Particle size distribution (related test methods)
• ISO 11125-3: Determination of hardness
• ISO 11125-5 to ISO 11125-9: Additional test methods (percentage defective particles, moisture, wear testing, etc.)
• ISO 11124 series: Specification and classification of metallic abrasives (see Annex A of ISO 11125-4:2018)

Refer to the full text of ISO 11125-4:2018 and linked parts of ISO 11124/11125 for normative details and implementation guidance.