Here is an image showing the pin diagram of this transistor.
Classification of hFE
The KSC3502-D transistor can have a current gain of 60 to 120. The gain of the KSC3502 will be in the range from 40 to 320, for the KSC3502-C it will be in the range from 40 to 80, for the KSC3502-E it will be in the range from 100 to 200, for the KSC3502-F it will be in the range from 160 to 320.
SMD Version of KSC3502-D transistor
The BF622 (SOT-89) and BF822 (SOT-23) is the SMD version of the KSC3502-D transistor. These transistors are of the same type, have similar parameters and are designed for surface mounting.
Replacement and Equivalent for KSC3502-D transistor