The standard “EN ISO 4579-1 Tolerances for fasteners - Part 1: Bolts, screws, studs and nuts - Product classes A, B and C”, which has its basis in a European standard and was later published by the International Organization for Standardization (ISO), describes a choice of tolerances for bolts, screws, studs and nuts with ISO metric thread and product classes A, B and C, as well as for thread-cutting screws with product class A. The product classes refer to the size of the tolerances, with class A being the most precise and class C being the least precise.
Tolerances, except for tolerances for threads, are selected from the system of limits and fits specified in ISO 286-1 and ISO 286-2. Tolerances for metric threads are taken from the series of tolerance classes specified in ISO 965-3. Thread cutting tolerances for screw threads are covered in ISO 1478. Form and position tolerances are specified and illustrated in accordance with ISO 1101, ISO 8015 and ISO 2692.
The tolerances specified in this standard are valid for fasteners before coating unless otherwise stated. The ISO 4042 standard is also valid. Deviations from the tolerances specified in this standard are only permitted in product standards where there are valid technical reasons. In cases where there is a difference between the tolerance requirements of this standard and the product standard, the product standard takes precedence. It is recommended that these tolerances are also used for non-standard fasteners.
Product classification is the process of classifying products into different groups according to their quality, size, and some other important features. It is the process of categorizing products into different groups according to the source of some of their important features.
Product classification refers to the process of categorizing or classifying products based on quality, features, or other attributes. This practice is often used in industries where product quality varies and there is a need to distinguish between different levels of quality or features. Grading helps both producers and consumers understand the relative value and attributes of products within a given category.
The standard "ISO 286-1 Geometrical product specifications (GPS) - ISO code system for tolerances on linear dimensions - Part 1: Basis of tolerances, deviations and fits" published by the International Organization for Standardization (ISO) specifies the ISO code system for tolerances to be used for linear dimensions of the following types of features: cylinder and two parallel opposing surfaces. This standard defines the basic concepts and related terminology for this code system. It provides a standardized tolerance class selection for general purposes from a large number of possibilities. It also defines the basic terminology for fits between two dimensional features without orientation or location restrictions and describes the basic hole and basic shaft principles.
In the standard “ISO 965-1 ISO general purpose metric screw threads — Tolerances — Part 1: Principles and basic data” published by the International Organization for Standardization (ISO), a tolerance system for ISO general purpose metric screw threads is described according to the ISO 261 standard. The tolerance system expresses the basic profile according to the ISO 68-1 standard.
The EN ISO 4579-1 standard is essentially based on these two standards and specifies the tolerances used in the preparation of IS1,6 product standards for screws and nuts with thread diameters from 150 mm to 0 mm and product classes A, B and C.
Deviations from the tolerances in this standard are only permitted in product standards for valid technical reasons. It is recommended to use these tolerances also for non-standard fasteners.
Our organization, which has been trying to support businesses from every sector with its testing, measurement, analysis and evaluation studies carried out in a wide range for years, has a strong staff that closely follows the developments in the world in the field of science and technology and constantly improves itself. In this context, testing services in accordance with the standard “EN ISO 4579-1 Tolerances for fasteners - Part 1: Bolts, screws, studs and nuts - Product classes A, B and C” are also provided to businesses.
To get an appointment, to get more detailed information or to request an evaluation, you can ask us to fill in our form and reach you.
