One of the biggest misconceptions about the particular type of kitchen tool you see above is the belief that it's a knife sharpener. It doesn't help that many manufacturers sell their honing steels as such. But a honing steel is not a sharpener. Ridged, rod-like honing steels, or "stropping irons," as they're sometimes called, do not sharpen blades; they realign them.
I recently attended a wedding at a 13th-century Welsh castle. For dinner, each table was served a massive roast leg of lamb. Because I cook for a living, I was the designated carver at mine. I stood up, drunk on Welsh ale, and, with a bit of dramatic flair, rapidly steeled my slicing knife's blade against the metal handle of the carving fork. But, drunk on Welsh ale, I accidentally sliced my finger open. To save face, I pressed my wounded finger into my palm to stanch the flow of blood. Then I fully carved the joint of meat, served it to the diners, pivoted on my heels, and made a beeline for the bathroom.
There are a few lessons to be learned here. First, you can hone a knife on quite a few things, including the metal handle of a carving fork, though I don't recommend it—tools that aren't designed for the task won't necessarily be as good at it, and, perhaps more importantly, they lack safety features like protective crossguards to separate your dainty fingers from the blade. I learned this the hard way.
Second, don't play with knives when drunk. Actually, don't play with knives, period.
Third, while the knife did indeed cut me, it was not because I had just sharpened it. No, I had honed the knife, and there is a difference.
What Is a Honing Steel For?
To understand how a steel works, it helps to think of a blade's beveled edge as a really pointy mohawk. When a blade is freshly sharpened, it's like a perfect mohawk, the hair converging to a fine point, with the help of far too much gel. But with use, that pointy edge starts to flop over on itself, making it much less effective, the way that mohawk gets when the gel has worn away over the course of a day.
With knives, this happens on a microscopic level—it's not something you can see by looking at it with the naked eye. But it is something you can feel. Your knife, which may have previously felt sharp as a razor, starts to bite and catch on the food you're cutting. You can sense some resistance that wasn't there before. By running the blade along a honing steel, you can pull that microscopic edge of metal back into an upright position, and regain a good deal of its cutting power in the process. It's sort of like applying fresh gel to a flopped-over mohawk. (See here for step-by-step directions on how to hone a dull blade.)
Eventually, though, that super-fine edge of metal will break off and wear away, like a pencil point dulling down. As this happens, the honing steel will become less and less helpful. Your only good option then is to re-sharpen the knife, which rubs away metal on a whetstone to create a brand-new edge, just as a pencil sharpener puts a new point on a pencil. (See here for instructions on how to sharpen a knife on a whetstone.)
So How Often Should I Hone, and How Often Should I Sharpen?
You can hone a knife as often as you want. I do it any time I start to sense that the cutting power of a knife is fading, which can be as frequently as multiple times a day, given how much I cook. Once you begin to notice that the honing isn't doing much, though, it's time to break out the whetstone (or send the knife to a sharpener, if you don't want to do it yourself) to give the knife a new edge. For a professional cook, sharpening on a whetstone can be a daily or weekly ritual. For home cooks, even once every six months would do wonders for most of the kitchen knives out there.
No matter which type of steel you choose, keep it clean and free of any metal residue by wiping it with a damp towel from time to time.
Buying a Honing Steel
Unlike most of the other equipment we review here at Serious Eats, a honing steel is a difficult tool to assess objectively. Because a blade changes every time it's used, and because honing and sharpening also change the blade, it's incredibly hard to compare one steel with another and come away with a clear sense of which one worked best.
Still, I've been playing with a few examples of each of the three main types—stainless steel, ceramic, and diamond—by using them on a variety of my knives at home, which vary in dullness and metal type (mostly stainless steel, along with a couple of carbon steel blades), then cutting vegetables to see how the honing had affected the knives' cutting ability.
Here's the short version: I found very little obvious difference between one steel and another in terms of how well they honed the knives. The diamond and ceramic steels had a slightly more noticeable effect, because those types actually remove some metal from the blade, but, as I'll explain below, that can be a mixed blessing.
In judging ease of use, what I found to be more important than anything else was the build of the steel itself. I found some handles more comfortable than others, and some steels more balanced and lighter than others.
One of the Most Important Considerations: Steel Length
No matter which steel you buy, one of the most important criteria in my mind is its length. The longer a steel, the more runway you have to pull the knife along. This isn't a big deal with smaller knives, like paring knives, but it matters when you're steeling longer ones, like chef's knives and slicers. (It's worth noting here that serrated knives can be honed only with great difficulty due to their teeth.)
As a rule of thumb, I'd recommend a minimum length of 12 inches—that's the measure of the steel rod itself, not including the handle. With a 12-inch steel, you'll be able to use the vertical honing method (described in the above-linked article) with little risk of the knife hitting the work surface below. If you have huge knives, of more than 10 inches in blade length, then you may want to seek out an even longer steel. For most of us, though, 12 inches is good.
Honing Steel Option 1: Stainless Steel
A stainless steel honing steel is the most classic version. It features a long, slender rod, usually with ridges running lengthwise along it (though smooth versions exist, too).
If you spend a lot of time on knife forums, you've probably read stuff about how you shouldn't try to hone a knife that's made from a harder metal than the steel itself. The logic there is that harder metal is more brittle, and therefore can be damaged on the steel. I have found no way to verify this without a microscope, and I haven't noticed any issues with my own extra-hard steel knives, but I suppose it's worth keeping in mind if you have knives made from especially hard steel, as many Western-style Japanese ones are.
Within this category of steel, I recommend the 12-inch steel by Winware. There's nothing fancy about it, but it's comfortable enough to hold and feels decently solid (if not top-tier), and, best of all, it's cheap as can be. I paid $8 for mine.
Like most metal steels, the Winware is magnetized, which means it'll hold on to any tiny bits of metal that might come off the knife, and prevent that stuff from getting in your food.
Honing Steel Option 2: Ceramic
Ceramic steels (which should maybe be called ceramics, not steels) are capable of rubbing off a teeny-tiny amount of metal from your knives as you hone them, which you can immediately see as gray streaks on the white ceramic rod. This means that they have a slight sharpening effect. Still, ceramic is gentle enough not to do anything too drastic to your blade in the process, so it's a nice choice for those who want to hone frequently while postponing true sharpening as long as possible. The main downside is that ceramic is brittle, so it's possible to break it if you're not careful.
My top pick for ceramic steels is made by DMT (Diamond Machining Technology), a company I learned about on knife forums that specializes mostly in diamond steels. It has a wide crossguard for maximum hand protection and seems especially well built, with a thick, solid plastic handle.
It's a little on the pricey side, though, so, for a slightly cheaper option, check out this one from Messermeister.
Honing Steel Option 3: Diamond
Diamond steels are perhaps the most controversial, since their abrasive diamond coating can remove more substantial amounts of metal during the honing process, making them a poor choice for daily honing. That said, running a knife on one occasionally can buy you even more time between true sharpening sessions.
I've seen a lot of negative reviews online for many of the diamond steels on the market, often with complaints about the diamond coating falling off or wearing away after just a short time. If you'd like to try one, though, this Messermeister won't set you back too far.
That's a good thing, because steeling yourself for sticker shock is an entirely different matter.