Cool Hand 4.5" Tapered Diamond Knife Sharpener Rod with Fish Hook, Gut Hook and Needle Sharpener, Grit 320/600, 2 Packs with Fine and Corse，Easy to Carry

Bought these to sharpen my serrated knives and works very well for that purpose. Can't comment on the ability to sharpen fish hooks but I imagine the fish hook groove would be good for sharpening pins , needles & safety pins.The covers are used as the handles for the sharpening rods which make them much easier to use.The process of sharpening serrated knives are very tedious involving angling the rods just at the right angle and stroking through each and every scallop serration in the knife. My 10 inch Victorinox bread knife has a LOT of teeth so it took awhile but the tapered rod did the job. Since the rods are tapered, it was more than large enough to sharpen the large scallops.Likewise, for my small 4 inch long serrated paring knife, the tapered rod tapered to a small enough diameter to sharpen the very small serrations (3 mm ~~ 1/16 inch wide serration scallops). Interestingly, the smaller knife was harder to sharpen than the bread knife because the serrations are so small hence easy for sharpening rod to slip out of the serration.TIP - after sharpening, there will be a burr on the back side of the knife which can be removed by passing the finer rod over the back side. I used a whetstone instead but the fine rod worked too when I tired it.NOTE - these rods are quite small, small enough that when they are in their tubular covers, both will fit into a closed hand.

I used these two files to sharpen 4 very dull large kitchen knives--20 years dull! Thus, this was not a simple matter of tuning up the edges, but rather essentially regrinding the nearly flattened scallops. Using only the top 1.5" of the files (which fit the scallops on the blades), the files cut very well through 3 knives, and barely make it through the 4th knife. The top 1.5 inches of the files were no longer usable at this point, but of course the lower parts of the files were still pristine, should I find a use for them. I consider this pretty good value given the low cost and will buy another set to keep the knives from ever getting that dull again. If I tune the knives up every 6 months I would expect these files to last through 3-5 years of service. I will say that the handles are not great, they tend to fall off, and if you attach the handle really tightly, it is hard to get off. But this is a minor annoyance. Of course it would be better if the files were longer and had more blade length with a diameter that matches my knives scallops, but no such file seems to exist. There are thousands of videos on YouTube on sharpening regular knives, a relatively trivial process, but little on sharpening the ubiquitous serrated kitchen knives. The whole field of sharpening serrated knives is wide open for innovation, inventors. Using these files is straightforward, but not necessarily easy or quick. I can easily envision sets of diamond wheels that could be chucked into a Dremel tool, for example, which do not currently exist on the market in the US for ordinary consumers. Probably these already exist in China, just a matter of importing them.

I needed a tool to sharpen my serrated knives, and these are the perfect tool. After using them, I do touch the knives up with a ceramic rod.

These worked well on my serrated pocket knives which have higher quality stainless and non stainless steels. Works very well on D2, 154CM, and 14cr28. It didn't suffer damage when I tried it on my M390, Elmax, and ZDP high HRC steels, but it will take some time to take metal off super steels. Best tool I've used for serrates. Recommend for regular to semi super steels.

best for serrated knives

I had hoped these would be bigger in length and diameter but these were very small when I opened the package. Smaller than I expected them to be based on the images on the posting. These need to be a little larger in diameter to be able to really sharpen larger diameter serrations like on bread knives, which is what I bought them for.

Nice size and easy to use. Keep your gear sharp!

Great for sharpening serrated knives!