That is surpising news, Jasper ... at least to me
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According to authority R.D.C. Evans and also to a few plug bayonets i have and had myself, always we have a pin-tang system, which runs full length of the hilt. Very, very rarely we have a push tang, where a short tapered tang passes through an aperture in the crossguard, the grip added by hammering it onto the remaining tang length, secured by friction or by gluing, a popular table-cuttlery method, visibly lacking in strenght. In any case, no rivets taking place ... at least that i have heard of
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