I think it's very unlikely that any modern crank arm has a 1/2" pedal thread. As far as I know, only one-piece cranks take 1/2" pedals. With that said, check BMX pedals because some BMX bikes are still made with one-piece cranks (thus taking 1/2" pedals). I have a pair of Diamondback BMX pedals on an old one-piece crank Schwinn.