The invention relates to a process for producing a large transmission gearwheel (1; 31; 36) consisting of a plurality of individual components, said process comprising the successive steps of: providing the individual components, which include at least one hub (2; 32; 37), a disc wheel (3, 4; 18, 19; 22; 24; 27; 33, 34; 38, 39) and a toothed ring (5; 20; 21; 23; 26; 35; 40) produced from case-hardened steel; at least partially mechanically soft machining the individual components; joining the individual components using a beam welding process; case hardening the individual components which have been joined to one another, and hard machining at least the toothed ring (5; 20; 21; 23; 26; 35; 40). The invention furthermore relates to a large transmission gearwheel produced by such a process.