Abstract: Electrodes of an electro-chemical machining tool are in the form of tubes which carry electrolyte to the surface of the article to be machined. The ends of the tubes adjacent the article are gripped between opposed clamping surfaces (13,14) of a block (10). One of those clamping surfaces 14 has a series of facets (15,16,17) with each facet inclined relative to the adjacent facet. The tubes are gripped between those facets (15,16,17) and serrations (18) in the opposed surface (13). This causes the tubes to have different orientations along the line of those tubes due to the relative inclination of the facets (15,16,17). This enables the tubes to conform to the trailing edge of e.g. a turbine blade.