http://www.rsw.com.hk/expert.htm
We were trying to make an upgrade for our RSW padded weapons and these were the first couple prototypes. It featured thinner blade cross section than the products of the other grades, while sharing approximately the same degree of shock absorption power along the edges with them. Well, maybe a little bit harder. For those who believed in "no pain, no gain" in martial arts training, this may be a bonus though. Nevertheless, the result was a more realistic appearing blade with the more discernable edges, flats and spine. Besides, the blade contacts and handling were better simulated too due to the reduced blade thickness. The only concern was hitting someone with the spine or flats of the sword, though. The reduced padding on these areas may inflict heavier impact upon your practice partners. Thus correct blade alignment during sparring was necessary, hence the name "Expert Grade". Of course, wearing padded armor like a gambeson would definitely help.
The spine and edge of the Expert grade Katana respectively.
The flat and edges of the Expert grade Bastard sword respectively.
Thinner cross section.