方管規格
- 6分 (19x19) / 1'' (25x25) / 1-1/4'' (30x30) / 1-1/2'' (38x38) / 2'' (50x50)
- 2-1/2'' (60x60) / 3'' (75x75) / 4'' (100x100) / 5'' (125x125) / 6'' (150x150)