Haidu Ceramic started designing the product more than ten years ago. First, it came to the market with a silicon carbide-based grey-colored grinding stone, which in 2019 changed to an aluminum oxide-based, light-colored stone.
The stones are entirely handmade.
There are two sets; a large full-size stone and a small stone with a rounded edge. The smaller stone works well as a sharpener for smaller knives, axes, and other tools. The larger stone is a cost-effectively priced, hard, and durable ceramic stone for sharpening knives, chisels, and hand plane blades.
The size of the larger stone varies, i.e., the size given is a reference. The length of the specimens measured between 220-235mm, and the width between approx. 65-75mm.
Please note that these stones will not fit into the holders sold by the HIOMAKIVI shop, so use either a silicone mat, wet rag, or similar non-slip mat under the stone when sharpening. I use a standard holder with one end resting on the buffer.
Now that I have more than two years of experience with stones myself, I can better comment on what HAIDU can do. I have started to use Haidu stones, especially the larger HCR 250 stone, for so-called rough knife repair. I have found that coarse stone is effective, especially for knife repair. I have been able to reshape broken tips with just this hand-operated stone. There has been no need to go to an electric machine for reshaping. The HCR250 stone did what I was looking for, after all. A rough stone and a quality one come in handy for every knife sharpener.