The S-372 is the replacement blade for the Gyokucho Tatebiki No. 372, a 240 mm professional rip dozuki for tenon cheeks, dovetails and other cuts along the grain.
It has the same specs as the blade on the saw: 0.3 mm thick and nickel plated, with a metal back, rip teeth at a 1.3 mm pitch (19.5 TPI) hardened to RC68 or more, a 0.51 mm kerf and a deep 55 mm blade that gives about 50 mm (2 in) of practical cut. Impulse-hardened teeth stay sharp a long time but aren't meant to be filed. When they dull, fit a new blade and keep your handle.
Gyokucho saws are made in Miki, Hyogo, by Razorsaw Kogyo, which was set up in 1969 when it developed the replaceable-blade saw. Gyokucho Sangyo, its sales company since 1975, sells them.