I have both a Swiss halberd and a German halberd that I need to haft. My question regards the riveting detail. Were washers used under the rivet heads as a common practice? Are there any extant examples of the langets being attached to the pole with both a rivet and a washer?

Thanks,
Bob

Depends on the period and purpose. A mass-produced munition weapon of pre-1500 is not likely to be decorated in that manner. After 1500, as the halberd began its long descent to a mere badge of rank, you see tassles and other decoration. A 16th c. guard's halberd might be elaborately decorated--tassle, etching, decorative rivet treatment, fabric covering of the haft, etc.

what time period are you interested in?

http://www.myArmoury.com/albums/thumbnails.php?album=13 might have some images tat relate.