Wire rope guardrails are supposed to be capable of withstanding a force of 200 pounds without failure, it must not deflect under pressure to less than 39 inches above the walking surface, and it must be at least a quarter inch in thickness to prevent cuts when installing around buildings. To install the metal guardrail safely, you must use a sufficient amount of clips on the wire to ensure that it will not snap under the pressure and to ensure that it is safe to walk on or use as a support.