... strength. and the other 5mm is the fold of the channel inwards. We have other specification below,41x 41x1.5 ... specification is available, too. We have ever exported perforated c channel pipe to Saudi Arabia, UAE, Nigeria,etc. Besides, our factory ... ., Ltd.Address (Beijing office): Room 2305,Block 10,Yiyuanju,Courtyard 4,Cuiwei Road, Haidian District, Beijing, ChinaPostcode: 100036Mobile phone: +86- ...