The coin isn't a 1 baht; the denomination is marked to either side of the coat of arms: "25 sa", or 25 satang.
Here be the correct WCG page.
Note that, while the coin bears the date 2500 (Buddhist calendar, = AD 1957) the coin was actually struck with this date "frozen" for quite some time, right up until AD 1987. There is no way to determine the actual date within that thirty year period when it was struck. This accounts for the rather high quoted mintage figure of 620 million.
Don't say "infinitely" when you mean "very"; otherwise, you'll have no word left when you want to talk about something really infinite. - C. S. Lewis