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ISO 6971:2002 pdf download

ISO 6971:2002 pdf download.Cranked-link drag chains of welded
construction, attachments and sprockets.
Specifications are also given for five types of attachment for use with the conveyor chains conforming to this International Standard.
2 Normative reference
The following normative document contains provisions which, through reference In this text, constitute provisions of this Intemabonal Standardlntei’national Standard. For dated references, subsequent amendments to, or revisions of. any of these publications do not apply. However, parties to agreements based on this International Standard International Standardare encouraged to investigate the possibility of applying the most recent edition of the normative document indicated below For undated references, the latest edition of the normative document referred to applies. Members of ISO and IEC maintain registers of currently valid International Standards
ISO 288-2. ISO system of limits and fits — Part 2: Tables of standard tolerance grades and limit dewations for holes and shafts
3 Chains
3.1 General
The chain is designed to operate with the closed end of each link in the forward direction to produce the maximum
scraping action against the material to be conveyed.
3.2 Nomenclature
The nomenclature of the chains and their component parts is specified in Figures 1 and 2.
3.3 Dimensions
Conveyor chain dimensions shall conform to those given in Table 1 (see Figure 3). Both maximum and minimum dimensions are specified to ensure interchangeability of links made by different chain manufacturers. Although these represent limits for interchangeability, they shalt not necessarily be regarded as limits of tolerance for manufacture,
3.4 Tensile strength
3.4.1 MinImum tensile strength
The minimum tensile strength is that value which shall be exceeded when a tensile force is applied to a sample which is tested to destruction in accordance with 3.4.2.
NOTE This mimmum tensile strength is not a working force. It le i’itended priardy as a comparative figure between chains of different construction, For application information, it is necessary to consult the manufacturers or their pubtished data.
3.4.2 Tensile testing
A tensile force, not less than the minimum tensile strength specified In Table 1, shall be applied slowly to the ends of a chain, containing a mmimum of three free pitches, by means of shackles so designed as to alow universal movement. The actual test method is at the discretion of the manufacturer.
Failure shal be considered to have occurred at the first point where increasing extension Is no longer accompanied by increasing force, ie. the summit of the force/extension diagram
Any test in which failure occurs adjacent to the shackles shall be disregarded.
3.5 Length accuracy
Finished chains shall be measured either in the dry state or after light lubrication.
The standard nominal length for measurement shall be that nearest to 3048 mm.
The chain shall be supported throughout its length and the measuring force specified in Table 1 shall be applied.
The finished chain length shall be equal to the nominal chain length
Chains that work in parallel may be matched by agreement between the purchaser and the manufacturer.
3.6 Designation
The designation numbers for welded.steel.type cranked link drag chains are based on the ISO chain numbers given In Table 1. These numbers are derived from those given to the cast type which they replace and have been given the prefix WD to indicate that they are of welded design.
3.7 Marking
The chains shall be marked with the manufacturer’s name or trademark and in addition should be marked with the appropriate ISO chain number given In Table 1.
The marking of the chawi shall not be obscured by the attachments.

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