All the dictionaries that I’ve come across agree on the following:
杆 is read as ‘gan1’ in Pinyin. It is a long pole, e.g. 旗杆 (flagstaff), 桅杆 (mast), 欄杆 (railing), 標杆 (surveyor’s pole), 電線杆 (electric pole, not 桿 as you’ve suggested), 撐杆跳 (pole vault), 杆塔 (tower), etc.
桿 is read as ‘gan3’ in Pinyin. It is a thin (rather than ‘small’) cylindrical object, e.g. 槍桿 (gun barrel), 筆桿 (pen-holder), 秤桿 (steelyard’s arm), 槓桿 (lever), 桿菌 (bacillus, which is shaped like a rod), 推桿 (push rod), 煙袋桿 (stem of a smoke pipe), etc.
高爾夫球gon1 (golf rod) is the only object that the dictionaries have different opinions. Most use 桿; just a few use 杆. Given that “rod” (as in 桿菌 and 推桿) is classified as “thin cylindrical object” instead of “pole”, I suppose 球桿 is the correct form.
杆 is read as ‘gan1’ in Pinyin. It is a long pole, e.g. 旗杆 (flagstaff), 桅杆 (mast), 欄杆 (railing), 標杆 (surveyor’s pole), 電線杆 (electric pole, not 桿 as you’ve suggested), 撐杆跳 (pole vault), 杆塔 (tower), etc.
桿 is read as ‘gan3’ in Pinyin. It is a thin (rather than ‘small’) cylindrical object, e.g. 槍桿 (gun barrel), 筆桿 (pen-holder), 秤桿 (steelyard’s arm), 槓桿 (lever), 桿菌 (bacillus, which is shaped like a rod), 推桿 (push rod), 煙袋桿 (stem of a smoke pipe), etc.
高爾夫球gon1 (golf rod) is the only object that the dictionaries have different opinions. Most use 桿; just a few use 杆. Given that “rod” (as in 桿菌 and 推桿) is classified as “thin cylindrical object” instead of “pole”, I suppose 球桿 is the correct form.