One of the biggest advantages of manual knife sharpeners is their relatively low cost. In fact, the one that earned most recommendations in our sources is the bargain-priced AccuSharp Knife and Tool Sharpener 001 (*Est. $9). Its design could hardly be simpler: a plastic handle with a slot containing a tiny, replaceable tungsten carbide sharpening blade. You place the knife to be sharpened on a table, blade up, and hold the AccuSharp over it with the blade positioned in the slot. Then you pull the AccuSharp along the length of the blade, applying light pressure. Reviews indicate that it takes about 20 passes to sharpen a dull blade, be it straight or serrated.
The AccuSharp's design can be hard to adjust to. Testers at a foodie magazine and at the Washington Post say that they found it a bit unnerving at first to pull the tool over an exposed knife blade. Once they got past that, though, they found it produced a sharp edge quickly and easily. Owners posting reviews at Amazon.com and Cooking.com agree that the AccuSharp is effective and easy to use and, though a few say the edge sharpness isn't really professional quality. Owners also like its compact size and low price tag. The most common complaint we saw is that the AccuSharp can take off a lot of metal, as well as some complaints about knives getting nicked.
Unlike most sharpeners, the AccuSharp only has one sharpening surface. While it can tackle the dullest knives, it can also be rough on the blades because it doesn't offer a finer surface for touch-up work. For multi-stage manual sharpening, we found the best reviews for the Spyderco 204MF Tri-Angle Sharpmaker System (*Est. $55). This rod-system sharpener is more complicated than the AccuSharp, with two sets of triangular rods that fit into its plastic holder at preset angles. Users pull the knife in cutting strokes against one rod and then the other (an included DVD shows you how to do this, since it's hard to describe). In addition to straight-bladed knives, the system can sharpen serrated knives, sporting knives and even scissors.
Professional reviews for the Spyderco sharpener are mixed. Chad Ward, writing for eGullet.org, says it's "pretty much foolproof," and Pete Thibodeau describes it in the LA Times as gentle on blades and easy to use. However, in tests at a cooking magazine, the Spyderco is described as slow and difficult to control, though it does eventually produce a sharp edge. Hundreds of owners at Amazon.com generally find that it works well, but some detractors say the units they bought don't fit together properly and leave the blades no sharper than they were to start with.