Method for manufacturing at least one part of a device for mounting directly or indirectly on an arm of an earth-moving or material-handling machine, such as an excavator, tractor, harvester, forwarder or crane, whereby the device enables coupling and/or positioning (tilt and/or turn) of a tool (14), such as a bucket, grapple, fork, vibratory compactor or harvesting head, relatively to the arm of the machine. The method includes the steps of: a) forming a melt including unalloyed or alloyed ductile iron, b) casting at least one part of a device from the melt, c) allowing the at least one part of the device to cool, d) austenitizing the at least one part of the device, e) quenching the at least one part of the device, f) austempering the at least one part of the device, and g) allowing the at least one part of the device to cool.