| 1 | We need a 48"pipe wrench." | |
| 2 | In the head wound to the proximo line of pipe wrenches. | |
| 3 | The design feature and working principle of the new tongs are introduced. | |
| 4 | Pipe wrenches should be inspected regularly. Replace the heel and jaw section if found to be defective or worn out. | |
| 5 | The invention discloses a safety door mechanism for a pair of hydraulic oil pipe tongs. The safety door (2) is of one leaf; |