With expanding carbide technology geared specifically towards wood applications, we have been working with a metallurgical lab to best define what grade of carbide is the best, we have pretty well decided that we are going to continuing to offer our 15-R4 inserts in a formula that has been designed for working MDF, it has a bit coarswer grain, and while it appears very sharp, our new 15-R2 inserts are being made in a nanograin structure for wood, and acrylics,. The R-4 will take the abuse of natural stone and the harder Tru Stone materials as well as material with bark which contains sand. The 15-R2s will now peel wood with literally a razors edge, The thing to realize about carbide is it's very grain structure will control the microscopic sharpness of the edge, larger Carbide structure will not be as sharp as something with a 20 uf grain size and this leads to better finishes and better results, Also having these inserts made is costly on the initial set up we just made a bowl tool with an 18m round insert, but we have one 16mm coming with in 60 days that are comparable in size to the most popular tools that are supposed easy. Having worked in every part of large machine shops, I've been through this carbide thing for a long time, and even on steel and harden tool steel as well as having to micro finish solid carbide mill rollers and re-machine them and with the nice tools like a flatlap covered in Diamond, I never gave much thought to taking the required time to sharpen any inserts that way, I've sharpened and shaped a lot of Carbide from C-2 to C-7 and the junk in between. With the prices available from reasonable vendors, su7xch as Peter and Myself, it's really redundant to hone carbide inserts, just buy new ones and get on with making pens, bowls, and hollowforms.