A lubricating oil composition for an internal combustion engine, the composition including: a lubricating base oil comprising at least one mineral base oil or at least one synthetic base oil or any combination thereof, the lubricating base oil having a kinematic viscosity at 100° C. of 4.0 to 4.5 mm.sup.2/s and a NOACK evaporation loss at 250° C. of no more than 15 mass %; (A) a calcium-containing metallic detergent in an amount of no less than 1000 mass ppm and less than 2000 mass ppm in terms of calcium on the basis of the total mass of the composition; (B) a magnesium-containing metallic detergent in an amount of 100 to 1000 mass ppm in terms of magnesium on the basis of the total mass of the composition; and optionally (C) a viscosity index improver in an amount of less than 1 mass % on the basis of the total mass of the composition.

A lubricating oil composition for an internal combustion engine, the composition including: a lubricating base oil comprising at least one mineral base oil or at least one synthetic base oil or any combination thereof, the lubricating base oil having a kinematic viscosity at 100° C. of 4.0 to 4.5 mm.sup.2/s and a NOACK evaporation loss at 250° C. of no more than 15 mass %; (A) a calcium-containing metallic detergent in an amount of no less than 1000 mass ppm and less than 2000 mass ppm in terms of calcium on the basis of the total mass of the composition; (B) a magnesium-containing metallic detergent in an amount of 100 to 1000 mass ppm in terms of magnesium on the basis of the total mass of the composition; and optionally (C) a viscosity index improver in an amount of less than 1 mass % on the basis of the total mass of the composition.

Provided is an internal combustion engine lubricating oil composition having a major amount of an oil of lubricating viscosity; a combination of alkaline earth metal alkylhydroxybenzoate detergents; at least about 50 to about 500 ppm of boron from a boron containing detergent; a molybdenum containing compound in an amount to provide the lubricating oil composition from about 100 to about 1500 ppm molybdenum; a ZnDTP compound; where the composition comprises magnesium in an amount from about 100 to about 800 ppm, and calcium in an amount from about 500 to about 2000 ppm.

Provided is an internal combustion engine lubricating oil composition having a major amount of an oil of lubricating viscosity; a combination of alkaline earth metal alkylhydroxybenzoate detergents; at least about 50 to about 500 ppm of boron from a boron containing detergent; a molybdenum containing compound in an amount to provide the lubricating oil composition from about 100 to about 1500 ppm molybdenum; a ZnDTP compound; where the composition comprises magnesium in an amount from about 100 to about 800 ppm, and calcium in an amount from about 500 to about 2000 ppm.

An oil-well metal pipe according to the present disclosure has a pipe main body including a first end portion and a second end portion. The pipe main body includes a pin formed at the first end portion, and a box formed at the second end portion. The pin includes a pin contact surface including an external thread part, and the box includes a box contact surface including an internal thread part. The oil-well metal pipe according to the present disclosure also includes a resin coating containing a resin, a solid lubricant powder, and copper phthalocyanine on or above at least one of the pin contact surface and the box contact surface.

An oil-well metal pipe according to the present disclosure has a pipe main body including a first end portion and a second end portion. The pipe main body includes a pin formed at the first end portion, and a box formed at the second end portion. The pin includes a pin contact surface including an external thread part, and the box includes a box contact surface including an internal thread part. The oil-well metal pipe according to the present disclosure also includes a resin coating containing a resin, a solid lubricant powder, and copper phthalocyanine on or above at least one of the pin contact surface and the box contact surface.

A lubricating oil composition including: a lubricant base oil; (A) a triazole metal deactivator in an amount of 0.005 to 0.03 mass % in terms of nitrogen on the basis of the total mass of the composition; and (B1) a succinimide compound represented by the following general formula (1) in an amount of 0.0005 to 0.02 mass % in terms of nitrogen on the basis of the total mass of the composition: ##STR00001##
wherein in the general formula (1), R.sup.1 and R.sup.2 each independently represent a hydrogen atom or a C1-36 linear or branched chain alkyl or alkenyl group, and at least one of R.sup.1 and R.sup.2 is a C8-36 linear or branched chain alkyl or alkenyl group, and n represents an integer of 1 to 10.

A lubricating oil composition including: a lubricant base oil; (A) a triazole metal deactivator in an amount of 0.005 to 0.03 mass % in terms of nitrogen on the basis of the total mass of the composition; and (B1) a succinimide compound represented by the following general formula (1) in an amount of 0.0005 to 0.02 mass % in terms of nitrogen on the basis of the total mass of the composition: ##STR00001##
wherein in the general formula (1), R.sup.1 and R.sup.2 each independently represent a hydrogen atom or a C1-36 linear or branched chain alkyl or alkenyl group, and at least one of R.sup.1 and R.sup.2 is a C8-36 linear or branched chain alkyl or alkenyl group, and n represents an integer of 1 to 10.

Disclosed herein are improved lubricating compositions effective to prevent or reduce low speed pre-ignition in an engine, as well as to prevent or reduce corrosion of engine components. The lubricating compositions include a base oil combined with a calcium chelate complex, optionally in further combination with additional additives.

Disclosed herein are improved lubricating compositions effective to prevent or reduce low speed pre-ignition in an engine, as well as to prevent or reduce corrosion of engine components. The lubricating compositions include a base oil combined with a calcium chelate complex, optionally in further combination with additional additives.