, it remains a critical reference for legacy industrial designs, mechanical engineering drawings, and historical metallurgical data. Russian Gost Core Content of the Standard

Soviet metallurgical naming conventions differ significantly from Western systems like the Unified Numbering System (UNS) or the Aluminum Association (AA) designations. Under GOST 2685-75, alloys are designated using a combination of Cyrillic letters and numbers. Decoding the Symbols Aluminum (Base metal) К (K): Silicon (Silumin alloys) Ц (Ts / C): Zinc М (M): Copper Г (G): Manganese Н (N): Nickel

Understanding GOST 2685-75: Aluminium Casting Alloys Technical Standards

Sectioned rules mandate specific tensile strength ( σbsigma sub b ), elongation percentages (

(Aluminium casting alloys. Marks, technical requirements and test methods) was a Soviet Union state standard that strictly regulated the composition and quality of aluminum alloy castings.

| | Type of Alloy (Основной состав сплава) | Examples (Примеры марок) | | :--- | :--- | :--- | | I | Al-Si (Aluminum-Silicon) / Silumins | AL2, AL4, AL4-1, AL9, AL9-1, AL34 (VAL5), AK9 (AL4V), AK7 (AL9V) | | II | Al-Si-Cu (Aluminum-Silicon-Copper) | AL3, AL5, AL5-1, AL6, AL32, AK5M2 (AL3V), AK5M7 (AL10V), AK7M2 (AL14V), AK4M4 (AL15V) | | III | Al-Cu (Aluminum-Copper) | AL7, AL19, AL33 (VAL1) | | IV | Al-Mg (Aluminum-Magnesium) | AL8, AL13, AL22, AL23, AL23-1, AL27, AL27-1, AL28, AL29 | | V | Other Complex Alloys | Composite alloys not falling into the first four categories |

When downloading an official scan or archival version of the standard via online databases, the document details strict industrial protocols:

Defines how to perform chemical analysis and mechanical testing on test bars or casting specimens to ensure compliance. Accessing the Standard

Since GOST standards are official state documents from the USSR/Russia, they are widely archived. You can find them through the following methods: :

: It is important to note that GOST 2685-75 was superseded by GOST 2685-97 . If you are looking for current manufacturing requirements, you should likely seek the 1997 version.

But as she turned to page 29, she noticed something strange. Between Section 8 ( Determination of tin migration ) and Section 9 ( Test report format ), someone had inserted a single sheet of very thin, onion-skin paper. It was not part of the original standard. It was handwritten in the same blue ink as the margin corrections, but the handwriting was different—nervous, angular, almost frantic.

This article provides a comprehensive overview of GOST 2685-75, its technical specifications, applications, and how to find the official PDF document. What is GOST 2685-75?

Provide the for a specific alloy (e.g., AL4 vs. AL9).

: Specific impurity limits, such as iron content, are strictly defined for these methods.

GOST 2685-75, titled is a foundational standard that played a key role in the quality control of cast aluminum alloys across the USSR. Despite being superseded, it remains critical for professionals dealing with legacy equipment, certain manufacturing processes, and historical documentation.

Open the GOST 2685-75 PDF to the mechanical properties section. Compare the test result with the required yield strength. If lower, reject the batch.