Spring for Kelly Bar 406

We can offer many types of spring for kelly bar.Type as below: 355/377/406/445/470/508/558Name of productExternaldiameter(mm)Pitch numberLength/section(m)Rated torque(KN@M)Depth(m)Interlock kelly bar355310–1318027–363773\410–12.522027–444063\410–1523027–574193\410–1525027–574403\410–1525027–574703\410–1728027–655083\410–1732027–655303\410–2038027–765753\410–2142027–806303\410–2145027–80Friction kelly bar3554\510–1318036–603774\510–1420036–654064\510–1521036–704194\510–1525036