Abstract: A corrosion resistant coating and process comprises the following layers applied in sequence over a ferrous metal substrate: a micro-throwing nickel-zinc alloy plating; a zinc-nickel alloy plating containing 5 to 30 weight percent nickel; a galvanically protective zinc metal plating; and either copper, nickel and chromium (or chromium substitute) plating layers or a chromate conversion layer. The coating is preferably used with a steel fastener such as a bolt or drill screw in combination with a washer.

Abstract: A corrosion resistant coating and process comprises the following layers applied in sequence over a ferrous metal substrate: a micro-throwing nickel-zinc alloy plating; an optional galvanically protective zinc metal plating; a zinc-nickel alloy plating containing 5 to 30 weight percent nickel; and an organic coating such as paint. In place of the organic coating there may be utilized sequential layers of copper, nickel and chromium or chromium-substitute plating. The coating is preferably used with steel drill screw fasteners.

Abstract: A corrosion resistant coating and process comprises the following layers applied in sequence over a ferrous metal substrate: a micro-throwing nickel-zinc alloy plating; an optional galvanically protective zinc metal plating; a zinc-nickel alloy plating containing 5 to 30 weight percent nickel; and an organic coating such as paint. The coating is preferably used with steel drill screw fasteners wherein it also reduces installation torque and drill time.

Abstract: A process for making self-threading screw fasteners wherein only the cutting portions of the tip of the fasteners are hardened. The unhardened portions of the fastener remain ductile and are not subject to hydrogen embrittlement during subsequent plating to improve corrosion resistance. The process preferably comprises applying a radiation curable plastic coating over the drill tip followed by plating of a thin (minimum 0.0005 inch, 0.013 mm) layer of copper. The cured coating is then removed leaving an unplated tip. The screw is then subjected to a hardening process, wherein only the portions of the screw without the copper layer are hardened. The screw may then be plated conventionally with a corrosion resistant metal. The invention is further directed to the product of the process. A second embodiment for making screws suitable for extreme corrosion resistance is also described.

Abstract: A corrosion resistant coating and process comprises the following layers applied in sequence over a ferrous metal substrate: a micro-throwing nickel-zinc alloy plating; galvanically protective zinc metal plating; a zinc-nickel alloy plating containing 5 to 30 weight percent nickel; and an organic coating such as paint. The coating is preferably used with steel fasteners wherein it also reduces installation torque and drill time.

Abstract: A process for making self-threading screw fasteners wherein only the cutting portions of the tip of the fasteners are hardened. The unhardened portions of the fastener remain ductile and are not subject to hydrogen embrittlement during subsequent plating to improve corrosion resistance. The process preferably comprises applying a radiation curable plastic coating over the drill tip followed by plating of a thin (minimum 0.0005 inch, 0.013 mm) layer of copper. The cured coating is then removed leaving an unplated tip. The screw is then subjected to a hardening process, wherein only the portions of the screw without the copper layer are hardened. The screw may then be plated conventionally with a corrosion resistant metal. The invention is further directed to the product of the process. A second embodiment for making screws suitable for extreme corrosion resistance is also described.

Abstract: A process for making self-drilling, screw fasteners having improved corrosion resistance. The process comprises applying a frangible radiation curable plastic coating over the drill tip corrosion prior to the deposition of a heavy resistant plating on the remainder of the screw. The invention is further directed to the product of the process.

Abstract: A process for making self-drilling, screw fasteners having improved corrosion resistance. The process comprises applying a frangible radiation curable plastic coating over the drill tip corrosion prior to the deposition of a heavy resistant plating on the remainder of the screw. The disclosure is further directed to the product of the process.

Abstract: Novel micro-throwing alloy undercoatings, multi-layer coatings containing a novel micro-throwing alloy undercoating and method of improving the corrosion resistance of ferrous metal articles are provided in accordance with the invention. The novel micro-throwing alloy undercoatings are applied as an initial layer over ferrous metal and comprise a layer of alloy having micro-throwing power, such as nickel-cadmium, nickel-zinc, iron-cadmium, iron-zinc, cobalt-cadmium, cobalt-zinc or a ternary or quaternary alloy containing iron, nickel or cobalt in combination with cadmium or zinc. The method comprises application, preferably by electroplating, of a layer of novel micro-throwing alloy undercoating directly over ferrous metal, optionally followed by one or more layers of metallic or organic coatings which further contribute to improved corrosion resistance.

Abstract: Superior corrosion resistance is provided by an improved oil composition an aqueous emulsified phosphating oil, an effective amount of polyvinylpyrrolidone and metallic zinc powder dispersed therein, which is applied, preferably by immersion or spraying, to a phosphated metal surface.

Abstract: A multi-layer plating and method for improving the corrosion resistance of ferrous metal articles, such as steel fasteners, are provided in accordance with the invention. The multi-layer plating comprises, in sequence over a ferrous metal substrate, a layer of an alloy which has micro-throwing power, such as nickel-cadmium, nickel-zinc, iron-cadmium, iron-zinc, cobalt-cadmium, or cobalt-zinc, a layer of cadmium, cadmium-tin alloy, a dual layer of cadmium and tin, zinc or zinc alloy, a layer of copper, a layer of nickel, and a layer of chromium or a metallic chromium substitute. The method comprises plating, and preferably electroplating, the aforementioned layers of alloy and metals over an article having a ferrous metal substrate to obtain improved corrosion resistance.

Abstract: A multi-layer plating and method are provided for improved corrosion resistance of ferrous metal substrates and articles made therefrom. The multi-layer plating comprises a metallic coating comprising a layer of zinc or cadmium and a layer of tin, each of which are preferably between 0.00001 to 0.001 inches in thickness, followed by a layer, preferably between about 0.0001 to 0.000001 inches in thickness of either chromium or a metallic chromium substitute. The method comprises plating, and preferably electroplating, the aforementioned layers of metal over an article having ferrous metal base stock to obtain improved corrosion resistance.

Abstract: Bright, tarnish resistant and color stable ternary alloys of about 40 - 90% of tin, about 10 - 50% cobalt and about 1 - 28% of a third metal of Periodic Group II.sub.B, III.sub.A or VI.sub.B. Typical third metals are zinc, cadmium, indium, antimony or chromium. The alloys are electrodeposited from aqueous acidic baths at a temperature of about 50.degree. - 85.degree.C. and current density of about 5 - 45 A/ft..sup.2.

Abstract: The present invention provides a method of improving the corrosion resistance of a ferrous metal substrate by providing a non-ferrous corrosion resistant plated undercoating by steps of sequentially plating onto the substrate a first layer of copper of about 0.00015 to 0.0005 inches in thickness, a layer of zinc of about 0.0002 to 0.0005 inches in thickness and a second layer of copper of about 0.00015 to 0.0005 inches in thickness and, optionally, multiples of such zinc and copper layers, and thereafter subjecting the plated substrate to a thermal treatment sufficient to effect partial diffusion at the respective interfaces of each of the layers of copper and zinc to provide zones of non-homogeneous copper-zinc alloy of infinitely variable linear distribution of copper and zinc.

Abstract: Bright, tarnish resistant and color stable ternary alloys of about 40 - 90% of tin, about 10 - 50% cobalt and about 1 - 28% of a third metal of Periodic Group II.sub.B, III.sub.B or VI.sub.B. Typical third metals are zinc, cadmium, indium, antimony or chromium. The alloys are electrodeposited from aqueous acidic baths at a temperature of about 50 - 85.degree. C and current density of about 5 - 45 A/ft.