While attending a cocktail reception hosted by a local business incubator I overheard the founder of a startup repeat the saying “Iron Sharpens Iron”. This was the third time that week I was presented with the that old trope. Following the theory that once is an accident, twice is a coincidence, but three times is a conspiracy I decided it was time to uncover the truth behind “ISI”, and why it keeps being applied to businessry and managering. In short I wanted to know if iron actually sharpens iron.

Spying an old colleague at the dessert table, a colleague who also happens to be an expert in metallurgical engineering (the science of metals) I cornered him between the croque-en-bouche and the chocolate fountain to ask what I thought was a simple question: does iron really sharpen iron? A short chuckle quickly lead to a slow groan and a quick shake of his head.

“That one again,” he sighed. “If I had a nickel for every time I’ve heard that fallacy spouted off by some wannabe manager, I’d be rich. You know how many swords got sharpened by other swords in battle? ZERO. They got nicked, dented, bent, broken, and at the very least dulled. Sharpened? No. Let me explain once and for all why iron cannot, does not and WILL not sharpen itself.”

“First of all, iron isn’t a good material for sharpening,” he says while biting into a cream puff pried from the top of the croque. “To be truly sharp, a material must be hard. As far as metals go, iron isn’t. It’s like sharpening…well it’s like sharpening this piece of cake” he replied while quickly eating a piece of limoncello sponge. “What you want is iron with just a dash of carbon, not too much, just a percent or two and suddenly,” grabbing a chocolate dipped strawberry to use as a pencil and sketching the iron-carbon phase diagram on a table cloth, “poof, you have steel.” Adding, “but not too much or you’ll get cast-iron which also isn’t good for sharpening” while pointing to the 3% line on the now chocolate smudged cloth before dispatching the fruit in one gulp.

Fallacy number one: Iron can effectively be sharpened.

Truth: Iron can’t be sharp so it can’t sharpen itself.

So Steel Sharpens Steel?

“Well, maybe kinda, but really no,” he says while cramming a snickerdoodle into his mouth. “You see, materials of equal hardness can’t really sharpen each other, at least not quickly and certainly not well. Ideally, if you rub two pieces together, one needs to be harder than the other to be capable of removing material and creating an edge. Otherwise, both just get dull. It’s like trying to sharpen this macaron with another macaron,” he says rubbing the two cookies together to demonstrate before consuming them both.

Ah-ha! I exclaimed, having caught him. What about the sharpening steel chefs use to sharpen knives, that’s steel sharpening steel.

“True, but only sort of,” he answered while consuming a cherry-marzipan chocolate truffle. “While you are making the knife sharper, you are not creating a sharpened edge, but simply straightening a bent one. You can’t take a block of metal and rub it on a sharpening steel and expect to get a knife. What you’ll get is tired. Try beating two cast iron pans together and see how sharp they get. I’ll save you the work, they don’t.”

“No, what you need”, he continued between bites of apple torte, “is something harder, like ruby or diamond. When I say ruby, what I mean is anything from the mineral class corundum, or maybe a nice aluminum or chromium oxide. Think sandpaper, or grinding wheels, or sharpening stones. That’ll do the trick nicely. These Napoleon torts will do nicely too!”

Fallacy two: Equivalently hard materials can sharpen each other.

Truth: One side needs to be harder in order to remove material

Corundum Sharpens Steel?

“Hell yeah it does!”, my friend exclaimed as he swallowed a mini creme brulee in two bites. “Ever seen a barber sharpen a razor on a stropping cloth, the cloth just holds the abrasive that does the actual sharpening. But it’s not as simple as just rubbing a knife across something abrasive. It takes knowledge, precision, patience, and if you’re doing it by hand, practice. Do it wrong and you’ll ruin both. Don’t forget, as your piece gets sharper, you need to decrease the size of the abrasive to take smaller and smaller bites,” making a point by eating another mini creme brulee in three bites this time.

Fallacy three: Just randomly rubbing two materials together will create sharpness.

Truth: You have to know what you’re doing.

The correct technique creates sharpness

“Now you’re on the right track. But you’re not there quite yet. Oh, did you try the double chocolate brownies? Very tasty,” he said reaching for seconds. “So start by taking some iron and adding a little carbon, and maybe some other stuff like molybdenum, vanadium, and chromium, then heat treat it appropriately.”

Quickly interrupting I asked about heat treating.

“Oh, yeah, you can’t just melt all this stuff together and expect a knife or saw blade or sword to pop out. You have to heat treat it to get the right material properties. Think of it like this chocolate chip cookie,” he says snatching a new confection from the table. “Before it’s baked it’s just a gooey mess. Delicious, I mean who doesn’t love cookie dough, but it’s not really something you can put out on a table. So you heat treat it by baking and presto-chango, a cookie!” he says grabbing another and breaking it in half to show the now transformed alloy of baked good and chips before consuming it.

Fallacy four: Any old piece of steel in any state will do.

Truth: You have to carefully manage the steel to make it appropriate for sharpening.

Additional processing is required

“If one were to be pedantic the correct saying might be: A selection of measurably harder abrasives correctly sized in the appropriate grits and skillfully applied will sharpen an alloy of iron, carbon and other elements mixed in the right proportions that has been correctly heat treated and then appropriately shaped.”

“That’s quite a mouthful” he said over a mouth full of dark cherry gelato. “But accurate.” Waving his spoon in the air he asked “What do you think of the saying from a businessery perspective?”

It’s complete and utter garbage spouted by managers looking to meaningless sayings to defend pitifully bad managering, while while trying to convince employees it’s for their own good and will in fact make them better. When in reality it just makes them dull, dented or bent, and always leaves them broken. Kind of like randomly bashing two pieces of iron together in the hopes they’ll magically become a shining sword. It’s not going to happen.

You read it hear first: Iron, does NOT sharpen iron.