Eastern Han

 
Ren 62. Wu Zhu. Notice the bar on the top side of the square hole. 2,3 gr.

Wu Zhu with a bar like the coin above, and with an extra wu character below. No references.

Variant of Wu Zhu. No references, I put it here because of the similar thin rim as above.

S 178a, Ding 511. Si Chu Wu Zhu . 3,7 gr. 
Issued by emperor Ling Di (A.D. 168-189) Zhongping 3 (A.D. 186). 
There are four lines radiating out from the center on the obverse.

 
Schjöth 179. Ding 512. Si Chu Wu Zhu . 3,5 gr. 
Issued by emperor Ling Di (A.D. 168-189) Zhongping 3 (A.D. 186).
There are four lines radiating out from the center on the obverse.

Schjöth 306. Clipped Wu Zhu. Inner part 0,85 gr.

Schjöth 304. Clipped Wu Zhu. Outer part 2,0 gr.