A method of hardening a surface of a ferro-alloy object, the method comprising at least partially gasifying a carbon-containing polymer to form a hardening material source; and exposing the object to the hardening material source, such that the hardening material source and the surface of the object react, thereby hardening the surface of the object.

A method of hardening a surface of a ferro-alloy object, the method comprising at least partially gasifying a carbon-containing polymer to form a hardening material source; and exposing the object to the hardening material source, such that the hardening material source and the surface of the object react, thereby hardening the surface of the object.

A gripping tool for gripping oilfield tubulars includes a gripping element having a substrate, and at least one gripping surface configured to engage an oilfield tubular, the at least one gripping surface being formed on the gripping element. The at least one gripping surface includes a coating on an outer surface of the substrate, the coating includes a carrier and a plurality of particles at least partially embedded in the carrier. The particles each have a hardness that is greater than a hardness of the carrier and a base metal of the gripping element, and the particles extend outward from the carrier and are configured to engage a structure that is gripped by the gripping tool.

A guiding member, having a body provided with a bore for mounting a mobile element is presented. The body consists of a metallic material. The bore has a surface layer treated against jamming over a diffusion depth of less than or equal to 0.6 mm. The surface layer has a hardness of greater than or equal to 500 Hv1 over a depth of between 5 and 50 ?m.

A guiding member, having a body provided with a bore for mounting a mobile element is presented. The body consists of a metallic material. The bore has a surface layer treated against jamming over a diffusion depth of less than or equal to 0.6 mm. The surface layer has a hardness of greater than or equal to 500 Hv1 over a depth of between 5 and 50 ?m.

A braking band having an annular band body arranged around a rotation axis and made of one of gray cast iron, steel, aluminum or alloys thereof, has at least one braking surface having an activated band body portion for increasing adhesive capacity of at least one protective surface coating placed on the surface of the activated band body portion and having at least one material with elevated resistance to abrasion. The activated band body portion is arranged on the surface of the annular band body to form an outermost layer of the braking band with the at least one protective surface coating and has a rough profile having at least one channel delimited by at least one pair of projections, extending along a path at least partially surrounding the rotation axis and having a channel bottom and a first channel side forming an acute angle with the channel bottom and an opposite second channel side forming an obtuse angle with the channel bottom.