BS ISO 501-2025 PDF

Full title and description

STB BS ISO 501-2025 — Hard coal. Determination of the crucible swelling number. This entry refers to the British-adopted version (BS ISO 501:2025) of ISO 501:2025 and is also circulated in some national catalogues under the STB label (national adoption/availability).

Abstract

This document specifies a laboratory method for determining the swelling properties of hard coal when heated in a covered crucible. The measured value is known as the crucible swelling number (CSN), also commonly referred to as the free swelling index (FSI). The method, test conditions and reporting requirements enable reproducible comparison between samples.

General information

• Status: Published / Definitive (BS adoption of the ISO document).
• Publication date: ISO original published May 1, 2025; BS ISO (national publication/adoption) published in early June 2025 (BSI catalogue date shown as 3 June 2025; tracked-change edition available mid-June 2025).
• Publisher: International Organization for Standardization (original); British Standards Institution (BSI) for the BS ISO adoption; catalogued under STB listings by distributors/vendors for national sale.
• ICS / categories: 73.040 (Coals); 75.160.10 (Solid fuels).
• Edition / version: ISO edition 5 (2025); BS ISO 501:2025 — national adoption of the 2025 edition.
• Number of pages: ISO PDF ~7 pages (ISO edition); the BS ISO published text is typically longer with national foreword and national annex(es) — commonly shown as 14 pages in BSI product listings.

Key bibliographic and publication details above are drawn from the ISO record for ISO 501:2025 and BSI / national catalogue entries for BS ISO 501:2025 and distributor listings.

Scope

The standard specifies a laboratory test procedure to determine the swelling behaviour of hard coal heated in a covered crucible; it covers sample preparation, apparatus, test procedure, expression of results, required reporting and method precision. The result (CSN/FSI) is intended for use in fuel and coke assessment, quality control and research concerning coking behaviour of coals.

Key topics and requirements

• Definition of the crucible swelling number (CSN) / free swelling index (FSI) and its interpretation.
• Preparation and representative sampling of test material (coal sample prep requirements).
• Apparatus specification (crucibles, furnace, temperature control and measurement devices).
• Test procedure: heating profile, hold times, cooling and measurement of swelling response.
• Calculation and reporting of CSN/FSI results, including repeatability/precision statements and required test report information.
• Requirements to ensure inter-laboratory reproducibility and comparability of results.

Typical use and users

Laboratories performing coal analysis, coking and metallurgical coke producers, coal quality control teams, fuel technologists, research institutes studying coal behaviour, and standards bodies or test houses that certify or compare coal/coke properties. Users rely on CSN/FSI results for quality assessment, blend formulation and process control in industries where coking behaviour matters.

Related standards

Standards in the same technical area include other ISO methods for coal analysis and coke testing (for example ISO 502 series on caking power / Gray‑King coke test and other ISO/TC 27/SC 5 outputs). This edition of ISO 501 (2025) replaces ISO 501:2012; national BS publications list the corresponding supersession (BS ISO 501:2012 → BS ISO 501:2025).

Keywords

crucible swelling number, CSN, free swelling index, FSI, hard coal, coking, coal testing, swelling test, crucible test, coal analysis, BS ISO 501, ISO 501:2025.

FAQ

Q: What is this standard?

A: ISO 501:2025 (published as BS ISO 501:2025 in the UK and circulated via national catalogues) is the international test method that defines how to determine the crucible swelling number (CSN) — a laboratory measure of how hard coal swells when heated in a covered crucible.

Q: What does it cover?

A: It covers sample preparation, apparatus, test procedure (including heating schedule), expression of results, precision of the method and the required elements of a test report so results are reproducible and comparable between laboratories.

Q: Who typically uses it?

A: Analytical and commercial testing laboratories, coke and metallurgical plants, coal suppliers and buyers, research organisations and anyone needing standardized measurement of coal swelling properties for quality control, blending, or research.

Q: Is it current or superseded?

A: This is the current (2025) edition of ISO 501 — it supersedes ISO 501:2012. The BS adoption (BS ISO 501:2025) is published as the definitive national text in 2025.

Q: Is it part of a series?

A: Yes — it sits within the ISO/TC 27 family of standards on coals and solid fuels; related methods for coal and coke (e.g., Gray‑King tests, sampling and other analytical procedures) are published under neighbouring ISO numbers and national adoptions.

Q: What are the key keywords?

A: Crucible swelling number (CSN), free swelling index (FSI), hard coal, coking, coal testing, crucible test, BS ISO 501:2025, ISO 501:2025.