Construction equipment uses double-acting cylinders that often operate with pressures up to 40 MPa (400 bar). These cylinders are designed to withstand many cycles and high mechanical loads. There is a high risk that the piston rods are subjected to external force or collapse. Therefore a design that can be removed easily for maintenance is often preferred. Such an embodiment is known as bolting construction. The piston rods are often induction hardened to resist external impact and strain.