What are the weak isospins (T3 values) of various hadrons, including the proton, neutron, mesons, hyperons and other hadrons? How is the weak isospin calculated for any hadron? Published sources provide T3 only for fundamental fermions, that is, quarks and leptons. In the fundamental bosonic sector, the photon's T3 is (0, 1), the gluon's is 0, the Higgs boson's is -1/2, the Z boson's is 0 and the charged weak bosons' is ±1. No such information appears for composite particles. One could calculate this using Q=T3+YW/2. However, the weak hypercharge (YW) values for hadrons are also not available. Supposedly, it is possible that the weak isospin of all hadrons is 0, since the weak interaction does not operate on the hadron as such, only on its constituent quarks. Is this the case? Thanks in advance.