Abstract: A cutting insert for chip forming machining tools is formed with a chip surface whose chip or rake angle increases with increasing cutting depth. In this manner the cutting edge becomes stronger closer to the operative cutting insert comer, where the work load is the largest. Simultaneously, the rake angle increases and the cutting forces diminish towards increasing cutting depth, where the specific work load is smaller.

Abstract: There is provided a sintered titanium-based carbonitride alloy for metal cutting containing hard constituents based on Ti, Zr, Hf, V, Nb, Ta, Cr, Mo and/or W and 3-30% binder phase based on Co and/or Ni. The structure contains 10-50% by weight well-dispersed Ti-rich hard constituent grains essentially without core-rim structure with a mean grain size of 0.8-5 .mu.m in a conventional carbonitride alloy matrix with a mean grain size of the hard constituents of 1-2 .mu.m. The Ti-rich hard constituent grains are essentially rounded, non-angular grains with an approximately logarithmic normal grain size distribution with a standard deviation of <0.23 logarithmic .mu.m.

Abstract: A cutting insert for milling tools comprises upper and lower, opposite surfaces (2, 3) of which at least the lower (3) is substantially plane in order to form a base surface to be supported by a cooperating supporting surface of the milling tool, opposite first and second side surfaces (6, 6') and opposite third and fourth side or gable surfaces (7, 7') which each forms a main cutting edge along an edge line that is distanced from the base surface (3), which main cutting edge at its opposite ends joins secondary cutting edges (10, 10', 10", 10'"). Each of the two side surfaces (6, 6') is inclined and forms an obtuse angle with the base surface (3). The two secondary cutting edges joining a common main cutting edge are located in a common plane that forms an obtuse angle with each imaginary plane being parallel with the base surface. The corner angle between a secondary cutting edge and the adjacent main cutting edge is equal at at least two diametrically opposite cutting corners (9).

Abstract: The present invention relates to cemented carbide bodies preferably for rock drilling and mineral cutting. Due to the fact that the bodies are built up of a core of eta-phase-containing cemented carbide surrounded by a surface zone free of eta-phase with low Co-content in the surface zone and successively increasing Co-content to a maximum in the outer part of the eta-phase-core they have obtained an increase in toughness and life at practical use.

Abstract: Flat drill bit for drilling holes in wood, comprising a plate (12) with two longitudinal sides (16,17), two main radial edges (14,15) and a pilot point with two converging pilot edges (18,19), where main radial edges, pilot edges and short lateral edges (24,26) being short portions of the longitudinal sides all have positive rake angle, produced by grooves parallel to the edges facing forwards during rotation. For larger diameters the pilot point has two converging pilot edges and two parallel sides (27,28).

Abstract: There is disclosed a new process for binder phase enrichment. The process combines binder phase enrichment by dissolution of cubic phase with the requirements that cause formation of stratified layers, resulting in a unique structure. The new structure is characterized by, in comparison with the ones previously known, deeper stratified layers and less maximum binder phase enrichment. The possibility of combining dissolution of the cubic phase with formation of stratified layers offers new possibilities to optimize the properties of tungsten carbide based cemented carbides for cutting tools.The new process offers possibilities to combine the two types of gradients. The dissolution of cubic phase moves the zone with maximum amount of stratified binder phase from the surface to a zone close to and below the dissolution front.

Abstract: Method for hardfacing of parts of the edges of a chainsaw guide bar, where the chain is guided by a groove, where a wear-resistant alloy is applied in a molten state to parts of the edges (12,13) of a guide bar blank and solidified in nearly final configuration, comprising the steps of:making a guide bar blank (10) having edges located at greater distance from the groove bottom (18) along the sides (17) which are not to be hardfaced than in those parts (12,13) which are to be hardfaced, andapplying a mold (15) with an extending plate (14) against the blank with the edge (23) of the plate in contact with the groove bottom (18), andfilling the space between the wall (19) of the mold and the edges (12,13) of the blank with a paste (16) made from finely powderized hardfacing alloy and a liquid, andheating the paste (16) locally to melt the alloy.

Abstract: There is now provided an oxide based ceramic cutting insert for chipforming machining of heat resistant alloys comprising a ceramic oxide based matrix and 5-50% by volume of homogeneously dispersed whiskers of silicon carbide. The whiskers have an average length of 4-7 .mu.m, with substantially all of the whiskers having a length less than 10 .mu.m.

Abstract: A cutting insert, preferably for milling cutters, comprises an upper side or chip surface, a bottom surface and side surfaces extending between the upper and bottom surfaces. At least one of the side surfaces having a relief surface adjacent to a cutting edge, which relief surface is helically twisted along the cutting edge so that the relief or clearance angle decreases with increasing cutting depth. This arrangement makes it possible to obtain an equally large clearance along the cutting edge even with a negative inclination of the cutting insert in the milling cutter body.

Abstract: A cutting insert comprises an upper side or chip surface, a bottom surface and side faces extending between these two surfaces. At least one side face is provided with a first, possibly helically twisted relief surface and under this first relief surface, a secondary relief surface. Between these two relief surfaces a recess is provided. With this recess, all grinding in the immediate proximity of the cutting edge is avoided. Further, by providing the recess, it is also made possible to precisely position the insert in the milling cutter body, even when the first relief surface is helically twisted.

Abstract: A cutting insert is produced by form-pressing and sintering of powder. The insert comprises a top chip surface, a bottom surface, and at least one edge surface extending between the top and bottom surfaces. The edge surface includes at least one relief surface portion which intersects the top surface at an acute angle to form therewith a cutting edge. A grinding operation is performed on the edge surface, but only along a lower portion thereof disposed below the relief surface portion, i.e., only along an area which is to be placed against a locating surface of a machine tool during a cutting operation.

Abstract: The present invention relates to a method of producing a sintered body comprising one or more hard constituents and a binder phase based on cobalt, nickel and/or iron by powder metallurgical methods milling, pressing and sintering of powders. At least part of the binderphase powder consists of non-agglomerated particles of spheroidal morphology having dimensions of 0.1 to 20 .mu.m.

Abstract: According to the present invention there is provided a method of manufacturing a compound body having at least one, partly covering layer on a porous body, whose pore system is evacuate by means of a subpressure which is applied on the porous body by a suction cup or the like and the body is dipped in a slurry of powdery components of the layer. The compound body is densified by sintering or other heat treatment, e.g., post-HIP.

Abstract: A cermet useful in the fabrication of metal cutting, rockdrilling and mineral tools, as well as wear parts. The cermet comprises (i) a hard phase of a simple boride of a transition metal, a mixture of simple borides of transition metals, or a mixed boride of transition metals; (ii) a binder phase of Fe, Ni, Co, Cr, or alloys thereof; (iii) a dispersion of particles of oxides of transition metals in which the oxygen can be replaced by nitrogen and/or carbon; and (iv) a dispersion of oxides of metals chosen from aluminum and Group IIA and IIIA metals.

Abstract: A circular saw blade is disclosed with narrow radial slots to avoid tangential stress. In order to lower the noise level and the cracking failure risk, a narrow arcuate cutout is provided in the direction of the slot adjacent to at least one end which cutout is not continuous with the slot. The parts of the cutout closest to the slot comprise at least one of the ends of the cutout, and the distance from the slot end to the nearest end of the cutout is less than the blade thickness.

Abstract: A tool is provided for the exertion of a turning moment, including an indication as to whether the turning moment exceeds a set value, in which a form piece (4) with parallel rectangular surfaces turns when the turning moment attains the set value and pushes a press bolt (3) situated in the shaft (2) and a indication sleeve (6) situated outside the shaft, said indication sleeve being connected with the press bolt, towards the grip (11) so that a previously hidden part of the indication sleeve (6) with a contrasting color becomes visible.

Abstract: A down-the-hole rock drill includes a top sub, a driver sub having a bore therein, and a piston case extending between and detachably connected to the top sub and the driver sub. A piston is located within the piston case, and a drill device is detachably connected to the driver sub. The drill device includes a shank and a head. The drill device also has a central passageway for a flushing medium. A tube is secured in the central passageway at a free end of the shank. The tube extends beyond the free end of the shank, and the piston has a central piston passageway that receives the tube. The piston is slidably movable relative to the tube. A first portion of the shank located closest to the head has a cross section, normal to a longitudinal center axis of the shank, in the shape of a multi-lobed figure that is continuously non-concave, and the bore of the driver sub is of a matching cross-sectional shape.

Abstract: Spiral drill comprising a cylindrical part with two chip grooves (15,16) and a principal maximum stiffness direction (22,23), an attachment part (30) with larger diameter connecting to the cylindrical part at a transition (14), and a tip with indexable cutting inserts (12,13), the chip grooves spirally encircling the cylindrical part to make the principal direction turn an angle C which is at least 110 degrees and at most 125 degrees.