Why Is Carbide Magnetic?
The cobalt binder, grade by grade — when a magnet sticking means nothing.
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CARBIDE MYTHS,BUSTED
Carbide has a mythology problem. Half of what gets said at the counter and in forums is wrong — and some of it costs people real money. Here are the five myths I hear most often, and what is actually true.
Magnet MythMelting PointGold CoatingsToughness
FIVE MYTHS, FIVE REALITIES
What people get wrong about carbide
Every one of these has cost somebody money. None of them survive the numbers.
Myth #1: "If a magnet sticks, it isn't carbide."
Busted. Some carbide grades are magnetic, and it is the cobalt binder's fault — cobalt is ferromagnetic, so higher-cobalt grades will grab a magnet while low-cobalt grades will not. I have watched this myth cost people money: a guy assumes his magnetic inserts are steel and tosses them in the steel bin. The magnet test rules steel out. It does not rule carbide in. Read the full story: Why Is Carbide Magnetic?
Myth #2: "You can melt carbide down at home."
Busted — and please don't try. Tungsten carbide melts at about 5,200°F. A propane torch runs around 3,600°F in open air, and no backyard foundry gets anywhere near carbide temperatures. This is exactly why the recycling industry never melts carbide at all — it reclaims the material with the zinc process and chemical routes that break it down without ever reaching a melt.
Safety note: grinding or overheating carbide can release cobalt dust, which you do not want in your lungs. Respirator and ventilation, every time — at home or in the shop.
Myth #3: "The gold coating adds value."
Busted. That gold titanium-nitride coating is a few microns thick — thousandths of a millimeter, thinner than a human hair — and it wears off in the first real cuts anyway. Coated or uncoated changes nothing about scrap value. Don't pay extra for it, and don't expect extra for it. The coating story in full: Carbide Coatings, Explained.
Myth #4: "All inserts are worth the same."
Busted. A clean, sorted insert is top-tier material. A brazed tip, a ceramic look-alike, or a mixed dirty bin is not. Form, grade, condition, and sorting all move the number — which is why I publish a firm $18–$20 a pound for clean, sorted inserts, end mills, and drills specifically, and quote everything else on its own merits. Sorting is not busywork; it is money.
Myth #5: "Carbide is indestructible."
Busted. Hard is not the same as tough. Carbide is one of the hardest materials in any shop and also one of the most brittle — it does not bend, it chips, cracks, and shatters under shock and vibration. Drop a carbide end mill on a concrete floor and you will learn this the expensive way. The upside for you: every shattered tool is still worth money as scrap. Broken is not worthless. Why Carbide Tools Break covers the physics.
| The myth | The reality, in one line |
|---|---|
| Magnet sticks = not carbide | Cobalt binder makes some grades magnetic; the magnet test can't confirm or deny carbide |
| Melt it down at home | Melts at ~5,200°F — no home setup gets there; recyclers don't melt it either |
| Gold coating adds value | Microns thick, wears off fast, worth nothing extra |
| All inserts worth the same | Form, grade, condition, and sorting move the price |
| Carbide can't break | Extremely hard, extremely brittle — chips and shatters, and the pieces are still worth money |
COMMON QUESTIONS
The numbers behind the myths.
What is the melting point of tungsten carbide?
About 5,200°F (2,870°C) — far beyond any home furnace or torch. That is why the recycling industry reclaims carbide with the zinc process and chemical routes instead of melting it.
Does the gold coating on my inserts add scrap value?
No. Coatings like titanium nitride are a few microns thick — thousandths of a millimeter — and wear off in the first real cuts. Coated or uncoated, it changes nothing about scrap value.
Why did my carbide end mill shatter?
Carbide is extremely hard but brittle — it does not bend, it fractures. Vibration, excessive stick-out, loose workholding, and shock loads chip or snap it. The shattered pieces are still worth money as scrap.
Are all carbide grades magnetic?
No. Magnetism depends on the binder — cobalt is ferromagnetic, so higher-cobalt grades can grab a magnet while low-cobalt grades will not. A magnet sticking does not prove or disprove carbide.
Is carbide harder than diamond?
No. Diamond is harder. Carbide is the hardest practical material in most shops, which is why it dominates cutting tools — but diamond tooling exists for the jobs carbide cannot touch.
I have worn carbide tools to sell. Do you buy small lots?
Yes — small lots are welcome, and every bucket counts, broken tools included. Shattered end mills and chipped inserts are still carbide. Call or text 312-880-8174.
MYTHS COST MONEY. PHOTOS DON'T.
Unsure What You're Holding? Send a Photo.
Here is my end, stated plainly. I pay a firm $18–$20 a pound for clean, sorted tungsten-carbide inserts, end mills, and drills. Brazed tooling runs lower and gets a custom quote. Sludge and tungsten heavy alloy get custom quotes from photos or assay. I pay within 24–48 hours. If a myth on this page ever made you throw good carbide in the wrong bin, the fix is free — call or text 312-880-8174 and I will tell you what you have got.