ASTM E399-24 PDF

Full title and description

ASTM E399-24 — Standard Test Method for Linear-Elastic Plane-Strain Fracture Toughness of Metallic Materials. This test method defines procedures, specimen configurations, and data-analysis requirements to determine plane‑strain fracture toughness (K_IC) and an optional size‑insensitive fracture toughness (K_ISi) for metallic materials under predominantly linear‑elastic, high‑constraint conditions using fatigue‑precracked specimens.

Abstract

ASTM E399-24 provides the mandatory K_IC test procedure and an optional K_ISi analysis (Appendix X1) for metallic materials tested in plane‑strain, linear‑elastic conditions. It specifies specimen types, minimum dimensions, fatigue precracking practices, loading and displacement‑gaging arrangements, validity requirements for test records and specimen size, and reporting conventions intended to produce reproducible fracture‑toughness values for engineering and research use.

General information

• Status: Active / Current standard.
• Publication date: January 9, 2024 (designated E399‑24).
• Publisher: ASTM International.
• ICS / categories: Mechanical testing of metals; fracture mechanics and materials testing (ICS code commonly referenced: 77.040.10).
• Edition / version: E399‑24 (revises E399‑23).
• Number of pages: 40 pages.

Scope

The standard covers determination of plane‑strain fracture toughness K_IC (mandatory) and optionally K_ISi (size‑insensitive value) using fatigue‑precracked specimens of several configurations (for example, compact tension C(T), single‑edge bend SE(B), disk‑shaped compact DC(T), arc‑shaped tension A(T) and arc‑shaped bend A(B)). Minimum specimen thickness for the standard K_IC procedure is 1.6 mm (0.063 in.) or greater; the document includes annexes detailing loading fixtures, displacement gage designs, specimen‑specific requirements, fatigue precracking procedures, rapid‑force testing, and special cases (e.g., hot‑pressed beryllium). The method is intended for linear‑elastic, high‑constraint situations and is not intended for materials that fail by cleavage or exhibit appreciable elastic‑plastic deformation (users are referred to E1921 and E1820 for such cases).

Key topics and requirements

• Definition and determination of plane‑strain fracture toughness K_IC with mandatory 2% apparent crack extension criterion for the K_IC procedure.
• Optional K_ISi calculation (Appendix X1) based on fixed crack extension (0.5 mm) to provide a less size‑sensitive toughness measure.
• Specimen configurations and dimensional/size‑validity requirements (C(T), SE(B), DC(T), A(T), A(B)).
• Fatigue precracking procedures and requirements to produce a sharp crack for testing; guidance for hot‑pressed beryllium and rapid‑force testing included in annexes.
• Requirements for test apparatus: displacement‑gage design, loading fixtures, and calibrated measurement of load and displacement.
• Validity checks for load record (P_max/P_Q), specimen size validity, and reporting conventions to ensure reproducibility.
• Limitations: not intended for cleavage‑dominated fracture or materials showing substantial plasticity at failure; alternative methods (E1921, E1820) recommended for those cases.

Typical use and users

Used by materials testing laboratories, fracture‑mechanics researchers, mechanical and metallurgical engineers, quality and certification laboratories, and organizations conducting failure analysis or design against crack growth and fracture. Industry sectors include aerospace, automotive, energy, pressure‑vessel and piping, and research institutions performing fracture‑toughness qualification and comparative material evaluation. Users apply the standard when a plane‑strain, linear‑elastic fracture‑toughness value is required for design, assessment, or material selection.

Related standards

ASTM E1820 (measurement of fracture‑toughness in elastic‑plastic materials), ASTM E1921 (determination of reference temperature for ferritic steels in the transition region), and various specimen/fixture annexes and normative references within the E399 document. E399 is published in ASTM Book of Standards Volume 03.01 and is developed under Committee E08 (Subcommittee E08.07).

Keywords

fracture toughness, K_IC, K_ISi, plane‑strain, linear‑elastic fracture mechanics, fatigue precracking, compact tension (C(T)), single‑edge bend (SE(B)), specimen size validity, displacement gage, fracture mechanics testing.

FAQ

Q: What is this standard?

A: ASTM E399‑24 is the Standard Test Method for Linear‑Elastic Plane‑Strain Fracture Toughness of Metallic Materials, providing procedures to determine plane‑strain fracture toughness (K_IC) and an optional size‑insensitive value (K_ISi).

Q: What does it cover?

A: It covers specimen geometries, minimum dimensions, fatigue precracking, test apparatus (gages and fixtures), loading rates and methods, data recording and analysis procedures for K_IC, optional K_ISi calculations, validity checks, and reporting requirements; annexes provide details for specific specimen types and special procedures.

Q: Who typically uses it?

A: Materials testing labs, fracture mechanics engineers, R&D groups, certification and quality assurance organizations, and failure‑analysis teams that need standardized plane‑strain fracture toughness values for metallic materials.

Q: Is it current or superseded?

A: Current — the E399‑24 edition (published January 9, 2024) is active and it revises the prior E399‑23 edition. Users should confirm they have the latest edition before testing.

Q: Is it part of a series?

A: Yes — E399 is part of ASTM's fracture‑mechanics and metals testing standards produced by Committee E08 (Book of Standards Volume 03.01). It is commonly used alongside related ASTM standards such as E1820 and E1921 for elastic‑plastic and cleavage/transition‑region fracture issues.

Q: What are the key keywords?

A: Fracture toughness, K_IC, K_ISi, plane‑strain, linear‑elastic, fatigue precracking, C(T), SE(B), specimen validity, displacement gage.