Bluehard blades are designed for precise and careful work, they have a slightly shallower angle on the toothline making them less aggressive than a standard ryoba and the sawplate is heat treated to be a little stiffer.
Blade Length
210mm
240mm
240mmfine tooth
270mm
Model No.
665
666
667
668
Blade Depth
70 - 87mm
65 - 83mm
65 - 83mm
79 - 96mm
Overall Length
530mm
560mm
560mm
645mm
Blade Thickness
0.45mm
0.5mm
0.45mm
0.6mm
Pitch XC
1.5mm16.9tpi
1.7mm14.9tpi
1.3mm19.5tpi
2.5mm10.2tpi
Pitch Rip
3.7-2.5mm6.9-10.2tpi
3.8-2.4mm6.7-10.6tpi
3.8-2.4mm6.7-10.6tpi
5.6-3.8mm4.5-6.7tpi
Set per Side
0.125mmm
0.125mm
0.125mm
0.125mm
Max Depth
∞
∞
∞
∞
Replacement Blade
S649
S650
S651
S655
Accepts Blades
S650S651S655
S649S651S655
S649S650S610
S649S650S651
Gyokucho razorsaws, the original replaceable blade Japanese saws, have long been renowned for their cutting efficiency and excellent durability. The latest generation of Gyokucho saws have blue handles made from TPE (thermoplastic elastomer) a remarkable material that is simultaneously hard and resilient yet feels velvety to the touch and affords a superb grip.
The blades of Gyokucho saws are treated using a process called electroless nickel plating, this has three functions. Firstly, it protects the blade against corrosion, secondly it provides a nice shiny mirror surface so you can gauge your cutting angles, and thirdly its low friction properties inhibit resins and sap from building up on the blade - anything that does manage to get stuck to them can easily be washed off with warm soapy water. The teeth are differentially impulse hardened, one by one, bringing the outer surfaces to RC68 or more whilst still leaving the 'root' of the tooth soft and therefore much less prone to fracture - not unlike tiny Japanese sword blades. They are equally happy working in softwoods or temperate hard woods and can, with care and a light touch, be used on exotic timbers too.
Ryoba are double edged saws (Ryo = Two, Ba = Edge). They have different tooth patterns on either side of the blade, usually one for ripping and the other for crosscutting.
Here's an interesting video by David Walton, YouTube's Unplugged Woodworker, on Ryoba Saw basics using a Gyokucho TPE saw.
