Question : Oracle -- SQL Results ?

Below works fine if I do one part,
but fails when trying to do BOTH parts.

How can I fix ?

select ipist.part_no,
Condition_Code_Manager_Api.Get_Condition_Code (Part_No,Serial_No,Lot_Batch_No) Condition,
sum(Qty_Onhand)
FROM INVENTORY_PART_IN_STOCK_TAB ipist
Where ((Qty_Onhand > 0
and part_no      = '411305' ))
--or part_no      = '.016 7075-T6 CLAD' ))
group by ipist.part_no, Condition_Code_Manager_Api.Get_Condition_Code (Part_No,Serial_No,Lot_Batch_No)

Answer : Oracle -- SQL Results ?

select ipist.part_no,
Condition_Code_Manager_Api.Get_Condition_Code (Part_No,Serial_No,Lot_Batch_No) Condition,
sum(Qty_Onhand)
FROM INVENTORY_PART_IN_STOCK_TAB ipist
Where ((Qty_Onhand > 0
--and part_no      = '411305' ))
--or part_no      = '.016 7075-T6 CLAD' ))
and part_no in ('411305','.016 7075-T6 CLAD' )
group by ipist.part_no, Condition_Code_Manager_Api.Get_Condition_Code (Part_No,Serial_No,Lot_Batch_No)