An burn-in socket used for connecting an IC package includes an base urged upward by springs, an actuated device floatably assembled on said base, a frame retained on said base, a plurality of contacts received in said base. The water-soluble metal working lubricant includes 85 mass % or less of water ; 5 to 75 mass % of a metal salt of an organic carboxylic acid wherein carboxylic acid residue has 8 or more carbon atoms in total and the acidalkali ratio by mole is 1:0. The sole and upper are substantially formed from molded plastic; the projections and recesses of the animal imprinting surface allow one wearing the shoe to make imprints on a soft surface, and the three dimensional figure on the outer surface of the upper relates to the print of the imprinting surface. The planing machine may have panel mounted on at least one of the base and the carriage assembly and extending between the carriage assembly and the base housing for preventing user contact with the cutterhead. The intersecting region of the ICF is darkened, such that a reduced amount of light from the light source passes through the intersecting region.