What are the British/European Standards for Scaffold Couplers?

The British/European standards for scaffold couplers are primarily specified in the EN 74 series of standards.The most important one is EN 74-1.Here is a detailed introduction:

Standard Number and Version:The current version is BS EN 74-1:2022+A1:2025.It replaced the previous version BS EN 74-1:2005.

Scope of Application:This standard applies to four types of friction-type scaffold couplers,namely right-angle couplers(RA),swivel couplers(SW),parallel couplers(PA),and sleeve couplers(SF).

Material Requirements:All components must be made of steel or cast iron,in line with the requirements of EN 12811-2.The bolt strength grade should be≥5.6(EN ISO 898-1),and an M14×2 bolt is recommended.The nut should be equipped with a washer,and the hardness of the washer is 200-300HV.

Design Requirements:After tightening,there should be a thread margin of≥2mm.The T-bolt head must be completely embedded in the base groove.The sleeve coupler should be designed with a self-centering device.

Performance Requirements:For right-angle couplers,the slip force Fs should meet the requirements of 7.0-10.0kN for class A and 10.0-15.0kN for class B;the breaking force Ff should be 20.0kN for class A and 30.0kN for class B;the bending stiffness cφis 15kNm/rad(steel).

Test Methods:Samples are randomly selected from a batch of≥500 pieces.The bolt connection torque is 50Nm,and the wedge connection is tightened with a 500g hammer.Five tightening-loosening cycles are required before the slip test,and the loading rate during the slip stage is≤2mm/min.

Marking Requirements:Each coupler should be permanently marked with information such as EN 74-1,the manufacturer's trademark,production year,and grade,with a character height of≥4mm.

In addition,EN 74-2:2009 is also a related standard,which is generally applicable to couplers connecting a steel tube with an outer diameter of 48.3mm and another steel tube with an outer diameter other than 48.3mm.