Abstract: To obtain a high tensile strength steel sheet which has an improved lubricating ability during press working, coating sharpness and defect-formation resistance, and which is useful as an outer plate of automobiles and electrical appliances, by forming uniform recesses and protrusions thereon and regulating the shapes of the recesses and protrusions, the recesses each having a flat portion at their bottom, and the size of the protrusion top faces, the depth between the recesses and the protrusions and the peak-to-peak distance being restricted. The recesses and protrusions formed thereon satisfy the following conditions; oil pools are formed thereon in an area covering 30% of the surface thereof; the top faces of the protrusions each having a size of 10 to 450 .mu.m; the level difference between the recesses and the protrusions being from 2 to 20 .mu.m; the peak-to-peak distance of the protrusions being from 50 to 1000 .mu.m; P and D satisfying the relationship 2.

Abstract: A method for processing the surface of a work roll, comprising forming a pattern coated with a cured product of a photosensitive resin composition on the surface of a work roll only at a predetermined portion, chemically etching the surface of the work roll at the remaining uncoated portions and peeling the cured product to form an uneven pattern on the surface of the work roll, wherein the composition comprises a visible light curable photosensitive resin composition and is cured by visible light irradiation.

Abstract: A method of removing magnetically-separated magnetic particles adhering to a magnetic filter. Sets of radially-arranged magnets are provided above and below, with adjacent magnets having unlike poles. The filter is located in an alternating magnetic field formed by the magnets. The filter is washed by directing a jet of fluid at it while magnets, or filter, is being rotated.

Abstract: Triurea grease compositions having excellent oil separation, shear stability, oxidation stability and structural stability of a thickening agent at a high temperature, which contains a triurea compound ##STR1## wherein R.sub.1 is a monovalent aliphatic hydrocarbon radical having 12-24 carbon atoms, R.sub.2 is a divalent triazine derivative radical, R.sub.3 is a divalent aromatic hydrocarbon radical having 6-15 carbon atoms or the derivative radical thereof, and R.sub.4 is at least one of monovalent aliphatic hydrocarbon radicals having 2-24 carbon atoms, derivative radicals thereof, monovalent aromatic hydrocarbon radicals having 6-10 carbon atoms and derivative radicals thereof, as a thickening agent in a usual lubricating base oil.