Bankok Bank ATM fee
Kasikorn Bank Bank ATM fee
Official site of Krung Thai Bank does not mention fee. I put the ATM card of Krung Thai Bank into the ATM of Siam Commercial Bank. I will test five withdrawals. A fee of 10 Baht is collected for the 5th withdrawal.
I checked it with online banking. 10 Baht is collected. Most Thai local banks are the same rule.
Citibank Thailand is free regardless of how many times you use ATM other than CitiBank. ATMs throughout Thailand connected by “ATM POOL” can be used for free. Also, you do not need the ATM card usage fee (hundreds of Baht / year) required by Thai local banks.