Blade: 6mm, 9mm, 15mm, 30mm, 36mm. Steel: High speed steel. HSS is so hard that it is difficult to grind, but you can grind it with a diamond whetstone. This set of chisels of this brand can be changed to different sizes. Please message us if you need the combination of sizes you require. The boxed set is only compatible with the 5 chisel set. Please message us if you would like to order a set with other sizes or number of chisels. The chisels in this set differ in the length of the handle of each size by a few millimeters. Although they are the same brand of chisels, this can be confirmed in the images. Please check these before purchasing with your approval. Thank you very much. This item is a chisel made by Yoshio Usui, a rare blacksmith in Japan who produces chisels with all HSS. This item is exactly the same, but the name is the wholesaler’s name. The item is exactly the same except that the engraving on the blade is different. It is a little more expensive than the regular Sukemaru. You can keep the sharpness even in hard work. It requires skill, but it can be sharpened like White steel. I finally had some time to sharpen the HSS chisel. It sharp easy on my diamond stones and it got very sharp. I then tested it on some American white oak and some Baltic Birch plywood which has many layers. It held up for about 50 hard hammer hits before the edge deformed & dulled. I was happy with the performance as those are 2 very hard materials and the plywood has glue and who knows what else in it. We will send you a new invoice and offer a discount. International Buyers – Please Note. ·We do not mark merchandise values below value or mark items as gifts US and International government regulations prohibit such behavior. Please see our other items. Please find a best item in.