Kennametal Cutting Tools: A Buyer's FAQ on Inserts, Nomenclature, and Actual Costs

I'm the person who orders the tooling at our company. About 60-80 orders a year across cutting tools, inserts, and shop supplies. That doesn't make me a machinist—but I've picked up a lot from the machinists I work with, and I've made enough mistakes to know what not to do. These are the questions people actually ask me about Kennametal cutting tools, plus a few I wish I'd asked.

How do I read Kennametal turning insert nomenclature?

The letters and numbers on a Kennametal insert look like a secret code—because they kind of are. But it's a standardized code, and once you know what each position means, you can read almost any insert from any major manufacturer.

The ISO/ANSI system for indexable insert designations is defined by ISO 1832 and, in the U.S., ANSI B94.4. The first seven characters encode, in order: insert shape, clearance angle, tolerance class, chip breaker style, inscribed circle size, thickness, and corner radius.

Take CNMG 432 as an example:

• C — shape: 80° diamond. Others you'll see often: S (square), T (triangle), D (55° diamond).
• N — clearance angle: 0°, the most common for turning.
• M — tolerance class: medium. Good enough for normal turning work.
• G — style: usually a hole with a chip former.
• 4 — size in 1/8" increments: 4 = 4/8 = 1/2" inscribed circle.
• 3 — thickness in 1/16" increments: 3/16".
• 2 — corner radius in 1/32" increments: 1/16".

Then there's the grade, like KC5010 or KCP25. That's Kennametal's coating and application code, and it doesn't follow the same logical pattern, so don't beat yourself up trying to memorize it. If I'm honest, I still check charts. The mistake I made early on? Assuming "similar" codes are interchangeable. They're not. The clearance angle matters, the corner radius matters, and the grade absolutely matters.

How do I pick the right Kennametal cutting tools?

Start with what you're cutting, not with what's on sale. That sounds obvious, but I've watched it go wrong in our own orders.

Four questions to ask:

1. Material? Steel, stainless, cast iron, aluminum, titanium? That drives the grade family.
2. Operation? Roughing wants toughness. Finishing wants a sharp edge and tighter tolerance.
3. Holder compatibility? The tool holder dictates the insert shape and clearance angle. Nothing else matters if it doesn't fit the holder.
4. Speeds and feeds? Pick a grade rated for the range you're actually running, not just what a sales sheet recommends.

For general-purpose steel turning, we end up on KCP25 or KC5010 a lot. But your jobs aren't our jobs, so treat that as a starting point, not a rule. Kennametal has a grade selector on their site, and their application engineers are genuinely helpful. I've used both.

One tip: when you find a combination that works, write it down. Machine model, holder, insert, grade, starting speeds and feeds. Future-you will be grateful.

Why do Kennametal inserts cost more than the no-name alternatives?

I get this question from finance every time I quote a tooling order. If you compare price per insert, the cheap options look like a no-brainer. But that's not the comparison that matters.

Here's a real example from our shop. On a typical steel turning job:

• Budget insert at about $3: lasted roughly 15 minutes of cutting time.
• Kennametal insert at about $7.50: lasted 40-45 minutes in the same operation.

Four cheap inserts per hour versus less than two premium inserts per hour. But the bigger cost was the changeover time. Every insert change is 8-10 minutes of stopped machine, plus getting back up to speed. At our shop rate, an hour of cutting time with the budget inserts cost us roughly $30 more once you counted the changeovers and the scrapped edges.

Everything I'd read before this job said the brand premium was just marketing. In practice, for our specific operations, the higher-priced insert was the cheaper one per good part. That's the total cost of ownership view, and it's changed how I quote everything. To be fair: your results will depend on your operation, your labor rates, and your materials. But run the math before you assume.

What's the biggest mistake a new buyer makes with cutting tools?

Ordering without verifying what's already in the tool holders. I did exactly that in my first year.

I found a great price on a batch of inserts—or rather, I thought it was great until the return fees. The per-unit cost dropped at 400 pieces, so I bought 400. Except the clearance angle didn't match our holders. $380 later in return shipping and rush freight on the correct order, I learned to check the nomenclature against the holder spec before hitting buy.

Second mistake: skipping confirmation because "it never matters." For a 316 stainless job, I knew I should double-check the grade from the last order. I figured it was basically the same, so I didn't call. That was the one time it mattered. The edges chipped on the first 40 parts. The scrap cost more than a phone call would have.

The fix is boring but effective: keep a list of every machine's tooling—holder model, insert shape, grade, geometry—and check it against every order. Boring, but it works.

Is a beginner 3D printer like the eufyMake actually worth it for a shop?

I get asked this a lot, usually by an engineer who just watched a video and wants to print their own jigs. And honestly, the answer has shifted over the last couple of years—budget printers got way better than they used to be.

The eufyMake is one of those entry-level FDM printers that keeps showing up in "best 3D printers for beginners" lists. We tested one for several weeks. For plastic fixtures, drill guides, soft jaws, and custom tool organizers, it did the job—not pretty, but functional.

Here's what surprised me: the machine was about $350, and it paid for itself after we stopped ordering fabricated plastic parts for two jobs. But the total cost is higher than the sticker. Filament is a recurring cost. Failed prints cost time. And somebody has to own the "why is this not dimensionally accurate?" conversations.

So: worth it for a shop with real plastic fixture needs. Not worth it if you're just curious.

What is the best 3D resin printer?

Nobody wants to hear "it depends," but with resin printers it really does. The best resin printer for a jewelry studio is different from the best one for a machining shop.

Resin wins on detail and surface finish, period. For investment casting patterns, small parts with fine features, and prototype parts that need smooth surfaces, it's the right direction. FDM just can't match it on those.

As for brands: Elegoo, Anycubic, and Phrozen all make solid machines at different price points. For a shop, pick a mid-size model with an active community and an established parts supply. The machine that people can still buy replacement screens for in three years is the one that'll still be running.

Be ready for the workflow, though. Resin is messier: bottles run about $30-60 each, you need washing and curing steps, gloves, fume management, and disposal considerations. It's not a "set it and forget it" thing. But for fine detail, nothing beats it in the sub-$1,000 range.

Anything else worth knowing before ordering Kennametal tools?

Don't hoard inserts because the unit price looks good at volume. I did that once and regretted it when a job changed and a box of inserts that fit nothing sat in storage for a year. Inserts have coated surfaces and shelf life, and slow-moving inventory is still cost.

And if you're new to this: use the manufacturer's tech support. I've called Kennametal's application team a few times—mostly for grade selection and speeds-and-feeds starting points. I want to say they respond within a day. That kind of resource has saved me from at least two bad purchases.

The bottom line is simple: price per insert isn't the number that matters. Cost per good part is. That's been the single most useful change in how I buy tooling.