Abstract: Ferritic spheroidal graphite cast iron includes: 3.1 to 3.5 percent by mass of carbon; 4.1 to 4.5 percent by mass of silicon; 0.8 percent by mass or below of manganese; 0.1 to 0.6 percent by mass of molybdenum; 0.1 to 1.0 percent by mass of chromium; 0.03 to 0.1 percent by mass of phosphorus; 0.03 percent by mass or below of sulfur; 0.02 to 0.15 percent by mass of magnesium; and iron.

Abstract: Ferritic spheroidal graphite cast iron includes: 3.1 to 3.5 percent by mass of carbon; 4.1 to 4.5 percent by mass of silicon; 0.8 percent by mass or below of manganese; 0.1 to 0.6 percent by mass of molybdenum; 0.1 to 1.0 percent by mass of chromium; 0.03 to 0.1 percent by mass of phosphorus; 0.03 percent by mass or below of sulfur; 0.02 to 0.15 percent by mass of magnesium; and iron.

Abstract: A method of die casting spheroidal graphite cast iron able to prevent formation of chill crystals to allow the crystallization of fine spheroidal graphite and simultaneously prevent the formation of internal defects, including the steps of preparing a die formed with a heat insulation layer at inside walls of a cavity, filling molten metal having a composition of the spheroidal graphite cast iron through a runner into the cavity, closing the runner so as to seal the cavity right before the molten metal in the cavity starts to solidify, and allowing the molten metal to solidify by the action of the inside pressure caused by crystallization of the spheroidal graphite in the sealed cavity.

Abstract: A method of die casting spheroidal graphite cast iron able to prevent formation of chill crystals to allow the crystallization of fine spheroidal graphite and simultaneously prevent the formation of internal defects, including the steps of preparing a die formed with a heat insulation layer at inside walls of a cavity, filling molten metal having a composition of the spheroidal graphite cast iron through a runner into the cavity, closing the runner so as to seal the cavity right before the molten metal in the cavity starts to solidify, and allowing the molten metal to solidify by the action of the inside pressure caused by crystallization of the spheroidal graphite in the sealed cavity.

Abstract: An apparatus for detecting the collision of a vehicle to produce a signal indicating the collision, which signal is adapted to actuate a safety device, such an apparatus having a pair of rotatable rigid members defining therebetween a space in which disposed is a stationary contact adapted to cooperate with a movable contact carried by the rigid members. Spring means are provided for biasing the rigid members in one rotational direction against a rotational force caused by deceleration of the vehicle. The rigid members are provided with a massive weight so as to make the gravitational center eccentric from the rotational axis thereof, thereby an enhanced sensitivity to the deceleration is obtained.

Abstract: A method for producing a heat-insulating casting characterized by placing a flexible ceramic semifinished product having a smooth surface, a modulus of elasticity of 200-5000 Kg/mm.sup.2, a bending strength of 8-200 Kg/cm.sup.2, and a wall-thickness less than 1/4 of the inside diameter, inside a casting mold, and casting molten metal so as to enclose the ceramic semifinished product.