An anaerobically curable composition comprising: a liquid anaerobically curable component; a solid anaerobically curable component; a solid thermoplastic polyurethane resin having a molecular weight in the range of from 40,000 g/mol to 100,000 g/mol and a melting point in the range of from 40°C to 80°C; and a curing component for curing the anaerobically curable components. Advantageously, the compositions of the invention are substantially solid and may be used as threadlockers.