Abstract: A method of manufacturing a milling cutter having a cutting head and a coaxial integral shank including grinding, in a first grinding operation, a plurality of helical flutes into the outer periphery of a cutter blank from a lead end using a peripheral area of a first grinding wheel generally of frusto-conical profile and rotatable about an axis generally transversely of the milling cutter axis, which peripheral area produces, simultaneously, the following three features: a leading face of a trailing tooth; a rear face on an adjacent preceding tooth; and a swarf removal gullet having divergent sides, grinding, in a second grinding operation, and using a peripheral edge of a second grinding wheel, a relief face, which extends rearwardly from a leading end of a tooth tip, resulting in a minimum tooth wedge angle of approximately 60°, and grinding, in a third grinding operation, a radius on the end of each flute.

Abstract: A method of manufacturing a milling cutter having a cutting head and a coaxial integral shank comprising the steps of grinding, in a first grinding operation, a plurality of helical flutes (5) into the outer periphery of a cutter blank from a lead end (24) using a peripheral area (16) of a first grinding wheel (15) generally of frusto-conical profile and rotatable about an axis (18) generally transversely of the milling cutter axis (1), which peripheral area (16) produces, simultaneously, the following three features: a leading face (9) of a trailing tooth; a rear face (10) on an adjacent preceding tooth; and a swarf removal gullet (13) having divergent sides, grinding, in a second grinding operation, and using a peripheral edge (19) of a second grinding wheel (20), a relief face (11), which extends rearwardly from a leading end of a tooth tip, resulting in a minimum tooth wedge angle of approximately 60°, and grinding, in a third grinding operation, a radius (23) on the end of each flute.

Abstract: A disc component 2 for a gas turbine engine is produced from a workpiece 4 by a sequence of machining operations. During the machining operations, the workpiece 4 is supported by a fixture 36 engaging support surfaces 32, 34. The workpiece 4 remains secured to the fixture 36 throughout the sequence of machining operations so that these operations can be conducted on both faces 26, 28 of a disc portion 8 of the workpiece 4 without removing the workpiece 4 from the fixture 36. The machining operations are conducted alternately on the opposite faces 26, 28 in order to allow residual stresses in the workpiece 4 to dissipate in a controlled manner.

Abstract: A clamp for clamping a workpiece such as a forging of an aerofoil component comprises a support body 24 to which a clamping member 26 is hinged. The clamping member 26 has a workpiece clamping element 54 having pads 58 for engagement with the workpiece. The workpiece clamping element 54 is pivotable relatively to the clamping member 26 by means of a ball and socket connection including a ball element 40. This enables the workpiece clamping element 54 to self-align with the profile of the workpiece, for example with a surface of the blade 6 of the aerofoil component. In an alterative embodiment, the workpiece clamping element 54 is formed integrally with the clamping member 26, but is connected thereto by a necked region of the clamping member 26 which permits flexure of the workpiece clamping element 54 relatively to the clamping member 26.

Abstract: A broach tool comprises a very stiff backing member and has an arbor adapted to be received into the hollow spindle of a machine tool, for example a multi-axis, computer controlled machining center. The backing member carries a plurality of cutting points disposed to perform successive cutting operations as the broach tool is pushed through a workpiece by relative movement of a worktable and the machine spindle. The broach tool is formed with externally extending passageways to supply coolant to the cutting points. The coolant may be supplied through the machine spindle.

Abstract: A method of high speed milling, and apparatus for performing the method, comprises directing a jet of hgih pressure coolant at the cutting zone of a rotary cutting tool. The jet of coolant has a delivery pressure of up to 500 bar at a flow rate of up to 60 liters per minute. The method is especially effective when used with a rotary cutting tool having at least 20 cutting edges and up to 100 cutting edges.

Abstract: A clamp for clamping a workpiece such as a forging of an aerofoil component comprises a support body 24 to which a clamping member 26 is hinged. The clamping member 26 has a workpiece clamping element 54 having pads 58 for engagement with the workpiece. The workpiece clamping element 54 is pivotable relatively to the clamping member 26 by means of a ball and socket connection including a ball element 40. This enables the workpiece clamping element 54 to self-align with the profile of the workpiece, for example with a surface of the blade 6 of the aerofoil component.

Abstract: A broach tool comprises a very stiff backing member and has an arbor adapted to be received into the hollow spindle of a machine tool, for example a multi-axis, computer controlled machining center. The backing member carries a plurality of cutting points disposed to perform successive cutting operations as the broach tool is pushed through a workpiece by relative movement of a worktable and the machine spindle. The broach tool is formed with externally extending passageways to supply coolant to the cutting points. The coolant may be supplied through the machine spindle.

Abstract: A rotary cutting tool formed with at least twenty helical cutting teeth.

Abstract: The material removal rate of a creep-feed grinding operation may be increased significantly by use of a type of porous grinding wheel in combination with jet of coolant liquid at high pressure directed at the periphery of the wheel in advance of the cutting point. The apparatus for performing the method may comprise a multi-axis machining centre adapted to enable the coolant nozzle(s) to be retracted to provide working clearance for automatic tool changer operation and to re-position the aiming point of the nozzle(s) over an angular range relative to a cutting point.

Abstract: Workpieces which are electrochemically machined, are exposed to corrosion and stray attack by the electrolyte, over surfaces which are not required to be machined. The invention provides a cowl 22 around the workpiece 10 and its fixture 12, a space 24 being provided at the plane of the interface between parts to be machined and parts not to be machined. De-ionized water is pumped into the interior of cowl 22, at a pressure just sufficient to prevent electrolyte entering gap 24, thus protecting the necessary workpiece portions and the apparatus.