ISO 4778:2019 specifies the requirements, methods of rating and testing of single, double, three and four leg welded chain slings of grade 8 using components such as sling chains according to ISO 3076 together with links according to ISO 16798, hooks according to ISO 7597 and forged components according to ISO 8539.NOTE 1 For special lifting purposes not covered by this document, additionally intermediate links can be used, for example to connect components to each other having different working load limit.The range of nominal diameter, dn, covered by this document is from 4 mm to 45 mm.Chain slings according to this document are for use in the temperature range ?40 °C to +400 °C according to ISO 3056.NOTE 2 Concerning the use and maintenance of chain slings of grade 8, see ISO 3056.Chain slings according to this document comply with the general conditions of acceptance of ISO 1834 and are used for symmetrically distributed loads only.NOTE 3 For rating of chain slings with asymmetrically distributed loads, see ISO 3056.This document does not apply to mechanically joined chain slings.NOTE 4 For mechanically joined chain slings, see ISO 7593.