... 21mm, 22mm, 23mmCertificationISO9001:2000, CE, SGSEN74 British type scaffolding pressed double Coupler :1) Material: Q2352) Surface: Zinc Plating, or hot ... galvanization or hot dip galvanization. Standard couplers are widely used with Ø48.3 steel scaffold tubes, we also produce ... , 60, 63 and 76mm. Also some special couplers are used for special functions, such as spigot support, deck retainer, ...