Metallic seals can be resistant to air leakage, resistant to degradation under heat, and capable of carrying mechanical loads. Various technologies--such as organic solar cells and organic light emitting diodes--need, at least benefit from, such metallic seals. However, these technologies involve polymeric materials and can tolerate neither the high-temperature nor the high-pressure processes of conventional metallic sealing. Recent progress in nanorod growth opens the door to metallic sealing for these technologies. Here, we report a process of metallic sealing using small well-separated Ag nanorods; the process is at room temperature, under a small mechanical pressure of 9.0 MPa, and also in ambient. The metallic seals have an air leak rate of 1.1 × 10(-3) cm(3)atm/m(2)/day, and a mechanical shear strength higher than 8.9 MPa. This leak rate meets the requirements of organic solar cells and organic light emitting diodes.