The present invention aims to provide a rigid polyurethane resin for cutting, which has high heat resistance, no scorching, and reduced expansion due to absorption of moisture in the air. The rigid polyurethane resin-forming composition (P) for cutting of the present invention includes: a polyol component (A); an isocyanate component (B); an inorganic filler (C); and a dehydrating agent (D). The polyol component (A) includes: 45 to 99% by weight of a polyphenol (j) alkylene oxide adduct (a), the polyphenol (j) having k functional groups where k is an integer of 2 or 3; and 1 to 55% by weight of a polyol (b). The polyphenol (j) alkylene oxide adduct (a) includes a total of not more than 39% by weight of a polyphenol (j) alkylene oxide adduct (ak) with at most k moles of alkylene oxide, based on 100% by weight of the polyphenol (j) alkylene oxide adduct (a), and has a hydroxyl value of 100 to 295 mg KOH/g. The polyol (b) is a multi-functional aliphatic or alicyclic polyol having 3 to 8 functional groups and has a hydroxyl value of 160 to 700 mg KOH/g. The weight of the oxyethylene groups included in the polyol component (A) is not more than 10% by weight in 100% by weight of the polyol component (A).