Length, the national authorities on the reinforced connecting sleeve is no uniform requirement. By the Ministry of Housing and Urban-Rural Development issued the "Regulations reinforced mechanical connection technology> (ie JGJ107-2010), the length of reinforced connecting sleeve no special provisions, Hengshui Branch source steel connection Equipment Co., Ltd. is a professional manufacturer of steel connection sleeve large companies, reinforced connecting sleeve length produced by our company are: φ16 40mm φ18 45mm φ20 50mm φ22 55mm φ25 60mm φ28 70mm φ32 75mm I produced the reinforced connecting sleeve in State Construction Engineering Quality Supervision and Inspection Center do form inspection. All products are disposable by the tensile test and inspection reports with the State Construction Engineering Quality Supervision and Inspection Center, report number is BETC-CL1-2011-235 to BETC-CL1-2011-243, to verify that the authenticity. www.chinataotong.com