GOST 26645-85 PDF

Full title and description

ГОСТ 26645-85 — «Отливки из металлов и сплавов. Допуски размеров, массы и припуски на механическую обработку» (English title commonly given: "Metal and alloy castings. Dimensions and mass tolerances and machining allowances"). The standard defines accuracy classes, dimensional and mass tolerances, machining allowances and requirements for control and designation of castings made of ferrous and non‑ferrous metals and alloys.

Abstract

GOST 26645-85 establishes rules and numerical limits for tolerances of sizes, form and location, surface irregularities, tolerances of casting mass and recommended machining allowances for castings. It provides classification of dimensional accuracy, degrees of warpage and surface accuracy, methods for indicating accuracy on drawings, and basic provisions for inspection and acceptance of castings. The standard applies to a wide range of foundry processes and casting materials.

General information

• Status: Withdrawn / cancelled for use in current national practice (listed as not valid / отменён in Russian catalogs; withdrawal/expiration entries appear in public registries).
• Publication date: Date of introduction (entry into force): 1 July 1987; many catalogs list a publication/release date of 1 July 1988. Users should note both dates when locating editions.
• Publisher: State standards body of the USSR (Gosstandart / national GOST system). Developed by relevant ministries and industry bodies during the USSR period.
• ICS / categories: Metallurgy — castings; commonly classified under ICS 77.140.80 and GOST group B83.
• Edition / version: Original designation GOST 26645-85 (with at least one documented amendment). Editions in commercial catalogs appear as the 1987/1988 issue.
• Number of pages: Typical electronic/booklet copies show about 34 pages (catalog entries vary between ~34–36 pages depending on publisher/printing).

Scope

This standard covers castings of black (ferrous) and non‑ferrous metals and alloys and establishes: permissible dimensional deviations (linear sizes, form and location), tolerances for mass of castings, recommended machining allowances and technological projections, classification of casting accuracy (dimensional classes, degrees of warpage, surface accuracy classes), rules for designation of casting accuracy on drawings, and general rules for inspection and control. It is intended for use by designers, foundry technologists and quality control specialists involved in drawing, manufacture and acceptance of castings.

Key topics and requirements

• Classification of dimensional accuracy for castings (classes and correspondence to casting processes and sizes).
• Numeric limits for dimensional tolerances (linear dimensions, form and location) for various classes of castings.
• Tolerances of casting mass and rules for indicating nominal mass, machining allowance, technological projections and actual casting mass on drawings.
• Recommended ranges of machining allowances ( припуски на обработку ) and technological allowances for common casting types and materials.
• Definitions and degrees of warpage (коробление) and criteria for surface accuracy and roughness of casting surfaces.
• Rules for designation of casting accuracy on technical drawings and examples of notation (e.g., "Точность отливки 8-5-4-7 См 0,8 ГОСТ 26645-85").
• Basic requirements for inspection and acceptance: types and methods of control (full, sampling), parameters to be checked and basis for conformity decisions.

Typical use and users

Primary users are foundry engineers, design and mechanical engineers, drafting offices, quality control/inspection laboratories, purchasing/procurement specialists sourcing cast components, and manufacturers of castings across industries (machinery, automotive, pumps/valves, instrumentation). The standard was used to set drawing specifications and acceptance criteria for cast parts and to harmonize tolerances across suppliers.

Related standards

GOST 26645-85 is part of the GOST family of standards on castings and links with other normative documents addressing testing, materials and drawing practice. Related documents and referenced standards include standards for cast iron and bronze grades, testing methods for castings, and drawing/technical documentation standards (examples often cited alongside GOST 26645-85: GOST 27208-87, GOST 3443-87, GOST 3212-92 and other foundry and testing norms). Some catalogs note links/replacements with other GOSTs in the series.

Keywords

GOST 26645-85; ГОСТ 26645-85; castings; foundry; dimensional tolerances; mass tolerances; machining allowances; surface accuracy; classes of accuracy; inspection; cast parts.

FAQ

Q: What is this standard?

A: It is a GOST (Soviet-era national standard) that specifies dimensional and mass tolerances, machining allowances and related rules for castings of metals and alloys.

Q: What does it cover?

A: It covers tolerances of linear dimensions, form and position, surface irregularities and roughness classes, tolerances of mass, recommended machining and technological allowances, classification of casting accuracy, marking/notation on drawings, and general control/inspection rules for castings.

Q: Who typically uses it?

A: Foundry technologists, mechanical and design engineers, drafting departments, quality control and inspection personnel, and procurement specialists dealing with cast components.

Q: Is it current or superseded?

A: Public registries and commercial catalogs list GOST 26645-85 as withdrawn/invalid for current regulatory use (entries show expiration/withdrawal dates in national catalogs). Users requiring binding requirements should consult the current national/regional standards registry or updated GOST/R and ISO standards for castings.

Q: Is it part of a series?

A: Yes — it belongs to the set of GOST standards addressing castings and metallurgical products (GOST group B83, ICS classification for metallurgy — castings). It is referenced alongside other casting and testing standards in technical documentation.

Q: What are the key keywords?

A: Castings, tolerances, machining allowance, mass tolerance, surface accuracy, ГОСТ, foundry, dimensional classes, inspection.