... factory 2.good bearing capacity British Type Scaffolding Single Coupler with EN74/BS1139 :Type: Forged Single coupler Single coupler ... 21mm, 22mm, 23mmCertificationISO9001:2000, CE, SGSBritish Type Scaffolding Single Coupler with EN74/BS1139 :1) Material: Q235,2) Processing method: drop ... vertical pole,the ledger,the corss braces,the tri-brackets,planks,and the base jacks,all these parts can be ...