How to make an attached blade of HAP 40 blade blanks
How to make an attached blade of HAP 40 blade blanks by ibuki blade staffs.
First, this making way is one of the general techniques. So please find a good way of manufacturing yourself.
1. surface rough smoothing, bent correcting
The blank has rust and oxide film on the outer layer. To make available the blank, you need to sand all face about 0.1 to 0.2 mm.
Also there are tiny bent, dent, warped in some cases. Please adjust it to flat.
How to fix curve of Japanese kitchen knives
Reference tools: sand paper, rubber hand whetstone, diamond whetstone. # low grit: about 100 to 200 
2. grind a core blade from outleyer stainless steel and to make the angle of the blade.
As a core HAP40 blade contained in the sus stainless steel, so you have to grind until you can check a core blade.
Please attach the blade angle to your favorite angle.
Reference tools: belt grinder, turn wheel machine whetstone
*There is a line of the blade in the picture. a line pattern that appears on the flat of a Japanese multi-layer knife as a result of the making process.
As Hap40 core blade is very hard and tough, you can set it to very thin edged too. 
Note: a core HAP40 blade part width 15 mm from cutting edge. Blade body and tang parts are made of SUS405 soft stainless steel. So you can change shape it easily.
3. setting a final cutting edged and surface finish
Also you can see the finished blades of our other customer by themselves.
Cool Mirror Polish blades with custom wa handle knives Customer Picture from Glen. S, Australia