BS EN ISO 12951:2015 pdf download – Leaf chains, clevises and sheaves — Dimensions, measuring forces, tensile strengths and dynamic strengths
This International Standard specifies the characteristics of chains used for general lifting purposes,together with the rim profiles of sheaves and the chain attachment ends of clevises. It gives dimensions,limits for interchangeability, length measurement, preloading, minimum tensile strengths and minimum dynamic strengths.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 606, Short-pitch transmission precision roller and bush chains, attachments and associated chain sprockets
ISO 15654 1) , Fatigue test methods for transmission precision roller chains and leaf chains ASME 2) B29.8, Leaf chains, clevises and sheaves
The nomenclature of chains is shown in Figure 1 (which does not necessarily define the actual form of the chain plates) and as given in Table 1 and Table 2.
3.2 Chain designation Leaf chain shall be designated by the prefix “LH” [“BL”] for chains derived from the ISO 606 A [ASME B29.8] series, or by the prefix “LL” for chains derived from ISO 606 B series, followed by a number of which the first two digits indicate the pitch expressed in sixteenths of an inch and the last two digits indicate the lacing (number of plates in the outer plate pitch and inner plate pitch). To obtain the ASME “BL” reference, the same principle is used, except that the pitch is expressed in eighths of an inch using only one or two digits, dependent on pitch.
EXAMPLE 1 A chain with nominal pitch of 12,7 mm derived from chain ISO 08B, consisting of outer plates and inner plates each comprising two plates would be designated by LL 0822
EXAMPLE 2 A chain with nominal pitch of 19,05 mm derived from ISO 12A [ASME chain No. 60], consisting of outer plates comprising three plates and inner plates comprising four plates would be designated by LH 1234 [BL 634]
The dimensions given in Table 1 and Table 2 provide minimum and maximum limits, ensuring interchangeability and connection to standard design clevises.
Manufacturers are responsible for the actual dimensional features of their products.
Chains from different manufacturers shall never be placed together within the same application.