This ferritic stainless steel sheet contains, by mass %: C: 0.001% to 0.020%; Si: 0.01% to 4.00%; Mn: 0.01% to 3.00%; P: 0.010% to 0.040%; S: 0.0001% to 0.0100%; Cr: 10.0% to 15.0%; N: 0.001% to 0.020%; Al: 0.50% to 10.0%; and either one or both of Ti: 0.05% to 0.40% and Nb: 0.05% to 0.40%, with the balance being Fe and unavoidable impurities, in which Cr/(Si+Al) is 10.0 or less, and a specific gravity is 7.6 g/cm.sup.3 or less.

A cutting blade (100) adapted to be carried by a tool holder (20) provided in a robotic work tool (10), the cutting blade (100) comprising a blade body (110) and a cutting edge (120, 121) extending along at least a portion of the periphery (111) of the blade body (110), and a slit (113) arranged to receive a pin (30) for attaching the cutting blade (100) to said tool holder (20), wherein the cutting blade (100) is movable such that the pin (30) may be displaced within the slit (113). The hardness of the cutting blade (100) decreases in direction from the cutting edge (120, 121) towards the center (125) of the blade body (110) such that the hardness of the cutting edge (120, 121) is higher than the hardness of at least a center portion (126) of the blade body (110). The present disclosure also relates to a method for manufacturing a cutting blade.

A wheel bearing arrangement for a vehicle, comprising at least one roller bearing, wherein at least one of the roller bearings is a ball bearing, which includes an inner ring and an outer ring, wherein both rings have raceways for balls being located between the rings. To ensure a sufficient lifetime of the roller bearings and to minimize the friction in the bearing, the at least one of the rings of the bearing arrangement is made from a ball bearing steel produced by a powder metallurgical process using a powder metallurgy component including 0.5 to 2.0 weight-% C, a maximum of 0.035 weight-% S, 3.0 to 5.0 weight-% Cr, 1.0 to 4.0 weight-% V, 1.0 to 12.0 weight-% W and 2.0 to 12.0 weight-% Mo, wherein at least one raceway has a radius and the balls have a diameter which fulfills the equation: radius/diameter>0.53.

A wheel bearing arrangement for a vehicle, comprising at least one roller bearing, wherein at least one of the roller bearings is a ball bearing, which includes an inner ring and an outer ring, wherein both rings have raceways for balls being located between the rings. To ensure a sufficient lifetime of the roller bearings and to minimize the friction in the bearing, the at least one of the rings of the bearing arrangement is made from a ball bearing steel produced by a powder metallurgical process using a powder metallurgy component including 0.5 to 2.0 weight-% C, a maximum of 0.035 weight-% S, 3.0 to 5.0 weight-% Cr, 1.0 to 4.0 weight-% V, 1.0 to 12.0 weight-% W and 2.0 to 12.0 weight-% Mo, wherein at least one raceway has a radius and the balls have a diameter which fulfills the equation: radius/diameter>0.53.

Provided is a magnetic refrigeration material represented by the formula La.sub.1-fRE.sub.f(Fe.sub.1-a-b-c-d-eSi.sub.aCo.sub.bX.sub.cY.sub.dZ.sub.e).sub.13 (RE: at least one of rare earth elements including Sc and Y and excluding La; X: Ga and/or Al; Y: at least one of Ge, Sn, B, and C; Z: at least one of Ti, V, Cr, Mn, Ni, Cu, Zn, and Zr; 0.03≦a≦0.17, 0.003≦b≦0.06, 0.02≦c≦0.10, 0≦d≦0.04, 0≦e≦0.04, 0≦f≦0.50), and having an average crystal grain size of not smaller than 0.01 μm and not larger than 3 μm, a Curie temperature of not lower than 250 K, and the maximum (−ΔS.sub.max) of magnetic entropy change (−ΔS.sub.M) when subjected to a field change up to 2 Tesla is not less than 5 J/kgK.

Provided is a magnetic refrigeration material represented by the formula La.sub.1-fRE.sub.f(Fe.sub.1-a-b-c-d-eSi.sub.aCo.sub.bX.sub.cY.sub.dZ.sub.e).sub.13 (RE: at least one of rare earth elements including Sc and Y and excluding La; X: Ga and/or Al; Y: at least one of Ge, Sn, B, and C; Z: at least one of Ti, V, Cr, Mn, Ni, Cu, Zn, and Zr; 0.03≦a≦0.17, 0.003≦b≦0.06, 0.02≦c≦0.10, 0≦d≦0.04, 0≦e≦0.04, 0≦f≦0.50), and having an average crystal grain size of not smaller than 0.01 μm and not larger than 3 μm, a Curie temperature of not lower than 250 K, and the maximum (−ΔS.sub.max) of magnetic entropy change (−ΔS.sub.M) when subjected to a field change up to 2 Tesla is not less than 5 J/kgK.

A Cr-based stainless steel sheet includes: 0.020 mass % or less of C; 1.00 mass % or less of Si; 1.00 mass % or less of Mn; 0.040 mass % or less of P; 0.0030 mass % or less of S; 10.0 to 18.0 mass % of Cr; 0.020 mass % or less of N; 0.10 mass % or less of Al; and one or both of 0.5 mass % or less of Nb and 0.5 mass % or less of Ti; in which a texture in a sheet surface satisfies (i) and (ii) below. (i) In the sheet surface, an area ratio of crystal grains ({211}±10-degree-oriented grains) whose orientation difference between a normal direction of the surface and a {211}-plane orientation is 10 degrees or less is less than 30%. (ii) For the {211}±10-degree-oriented grains, a length in a rolling direction and a length in a sheet width direction are each less than 0.15 mm on average.

A Cr-based stainless steel sheet includes: 0.020 mass % or less of C; 1.00 mass % or less of Si; 1.00 mass % or less of Mn; 0.040 mass % or less of P; 0.0030 mass % or less of S; 10.0 to 18.0 mass % of Cr; 0.020 mass % or less of N; 0.10 mass % or less of Al; and one or both of 0.5 mass % or less of Nb and 0.5 mass % or less of Ti; in which a texture in a sheet surface satisfies (i) and (ii) below. (i) In the sheet surface, an area ratio of crystal grains ({211}±10-degree-oriented grains) whose orientation difference between a normal direction of the surface and a {211}-plane orientation is 10 degrees or less is less than 30%. (ii) For the {211}±10-degree-oriented grains, a length in a rolling direction and a length in a sheet width direction are each less than 0.15 mm on average.

A Si-killed steel wire rod for obtaining a spring excellent in fatigue properties and a spring excellent in fatigue properties obtained from such steel wire rod are provided. In the Si-killed steel wire rod of the present invention, oxide-based inclusions present in the wire rod contain SiO.sub.2: 30-90%, Al.sub.2O.sub.3: 2-35%, MgO: 35% or below (not inclusive of 0%), CaO: 50% or below (not inclusive of 0%), MnO: 20% or below (not inclusive of 0%) and BaO: 0.2-20% respectively, and total content of (CaO+MgO) is 3% or above.

A Si-killed steel wire rod for obtaining a spring excellent in fatigue properties and a spring excellent in fatigue properties obtained from such steel wire rod are provided. In the Si-killed steel wire rod of the present invention, oxide-based inclusions present in the wire rod contain SiO.sub.2: 30-90%, Al.sub.2O.sub.3: 2-35%, MgO: 35% or below (not inclusive of 0%), CaO: 50% or below (not inclusive of 0%), MnO: 20% or below (not inclusive of 0%) and BaO: 0.2-20% respectively, and total content of (CaO+MgO) is 3% or above.