Abstract: A method is disclosed for improving the hydrolytic stability of the adhesive bond between an RFL type organic adhesive and the steel reinforcing element in steel-rubber composite articles. This is accomplished by a pre-treatment of the steel surface before it is coated with the organic adhesive. The pre-treatment is conducted in a continuous operation which includes the sequential steps of: (1) cleaning the metal surface by a vapor degreasing method or by immersion in a detergent containing aqueous bath followed by a hot water rinse; (2) coating the surface with a crystalline or microcrystalline zinc phosphate; (3) rinsing the phosphated steel surface with water; (4) subjecting the phosphated surface to a chromate or chromic acid rinse; (5) rinsing again with deionized water; and finally (6) drying the steel reinforcing element.

Abstract: The present invention is directed to an improved cutting tool blank formed by hot pressing a mixture of finely divided high-purity alumina and from about 0.05% to 0.35% of magnesia. Up to 0.10% nickel oxide may be present. The hot pressing temperatures are effected at a temperature in the range of about 1300.degree.C to 1525.degree.C so that the crystal size of the alumina in the tool blank has an average size range from 1 to 2 microns and the pressed blank has a final product density in excess of 3.97 grams per cubic centimeter. The preferred density of the blank is in excess of 3.98 grams per cubic centimeter. The hot pressing is conducted under vacuum conditions.