Kennametal KSEM Speeds & Feeds, Drift Theory, and Carbide Grades: A Machinist's FAQ

Eight years ago—my first year (2017) doing procurement for a contract machine shop—I placed an $8,000 tooling order and scrapped about $1,200 of it because I didn't check the application data. I've personally made and documented 14 significant ordering mistakes since then, totaling roughly $8,400 in wasted budget. Now I maintain our team's ordering checklist. This FAQ is that checklist in question form.

Here's what we'll cover:

• What makes Kennametal different as a company
• Whether it's only for aerospace and automotive
• The right way to set Kennametal KSEM speeds and feeds
• Why holes drift even when the tool looks fine
• Why there's no single carbide grade for everything
• How Kennametal pricing compares on cost per hole
• When you should not buy Kennametal
• How to get real support without a phone tree

1. What makes Kennametal different as a company?

Kennametal is a carbide and metallurgy company first, not just a tool distributor. That distinction matters because the grade and coating determine what the tool geometry can actually do. When I started, I thought a drill was a drill. Then I watched a Kennametal insert outlast a no-name insert on a steel job by roughly three to one, and I realized the metallurgy was the product.

They also carry a wide portfolio—drilling, milling, boring, turning, and mining tools—which means we can consolidate vendors instead of juggling ten catalogs. But "different" doesn't mean "perfect." It means the selection process needs to be just as careful. I don't have hard data on industry-wide tool costs, but based on eight years of orders, the total-cost difference is smaller than people assume. (In other words, purchase price is only part of the story.)

2. Is Kennametal just for aerospace and automotive?

No. Our shop started on general industrial parts, then moved into aerospace and energy. Kennametal covers both, and the same engineering that makes a tool work on nickel-based aerospace alloys also shows up in mining and oil-and-gas tools. In 2022, a mining customer of ours was testing a wear-resistant carbide solution on a tough mining extraction application, and the Kennametal tooling failed in a predictable way—worn edge, not broken body—which meant we could change the insert at the right interval instead of emergency-stopping the line.

That's the value: they bring material science to dirty environments too. If you're in oil, gas, or renewable energy, you don't need a separate brand strategy. You need a rep who can pull from the right product family. I learned this when I almost sent a standard steel insert to a customer running abrasive composites. The application engineer stopped me before the order shipped.

3. What's the right way to set Kennametal KSEM speeds and feeds?

The right way to set Kennametal KSEM speeds and feeds is to start with the book, not your gut. Kennametal publishes starting parameters for KSEM drills in its online catalog and Speeds & Feeds Manager. Use those numbers as a baseline, then adjust for machine condition, coolant pressure, and workholding rigidity.

The mistake I made in 2018? I pushed feed 30% above the recommendation because the machine "sounded fine." It wasn't fine. The insert edge broke, the head scraped the hole wall, and the part had to be reworked. That was a $700 error plus a two-day delay. The fundamentals haven't changed: speed controls heat, feed controls chip thickness. But execution has improved—KSEM's replaceable head design means you can put a fresh edge on without changing the body, as long as you respect the head's limits.

If you're new to KSEM, use the official starting point and drop the feed another 10% until the first test cut is stable. Then log the data and move up in small steps.

4. Why do holes drift even when the tool looks fine?

Drift is cumulative: tool wear, spindle thermal growth, and setup stiffness all push the tool slightly off-center. I used to think "drift theory" was one of those academic topics that didn't apply to a job shop. Then I started measuring hole position every 100 parts. The pattern became obvious. A new insert makes a hole at true position. At 200 parts, the cut loads up and the tool deflects. At 400 parts, you're outside tolerance even though the tool looks acceptable.

The reason is edge radius. A worn micro-edge changes the cutting forces, which changes the deflection. So I log Kennametal tool life in hours, not "until it sounds rough." You can also compensate for known drift in your program—if you know the curve. (And no, checking spindle growth once a year isn't enough.)

5. Can one carbide grade handle all my materials?

No. Carbide grade is a compromise between hardness and toughness, and you can't maximize both at the same time. Kennametal offers many grades because the real world has many materials—aluminum, alloy steel, cast iron, nickel alloys, hardened die steel, and abrasive composites.

I once ordered a "pretty good all-around" grade for a 4140 alloy steel job and spent a week fighting built-up edge. The right PVD-coated grade reduced cycle time by about 18%. (I don't have hard data on everyone's grade claims, but I do have that one job in my spreadsheet.) The lesson: let the material and operation pick the grade, not your old habits. A universal insert can make you money on simple work and cost you a lot on difficult work.

6. Is Kennametal worth the extra price?

The purchase price can be higher, but the number I trust is cost per hole. In Q3 2024, we documented 5,000 holes in a tool steel. A cheap insert was $2.70; the Kennametal insert was $5.20. The cheap one lasted 55 holes; the Kennametal one lasted 140. That works out to roughly $0.049 per hole for the cheap insert and $0.037 per hole for the Kennametal. Same machine, same program, same lot.

The upside of the cheap edge was a lower price per insert. The risk was a mid-job failure and a missed deadline. I kept asking myself: is saving $2.50 per edge worth potentially taking a hit on 5,000 parts? For production work, no. I still buy cheap inserts for low-volume prototype runs where the trade-off is acceptable. In 2021, a $3,200 bad batch came from "replacement" inserts bought through an online reseller. They looked right, but the coating quality wasn't there. Rework costs more than the savings, and that lesson only needs to happen once.

7. When should I not buy Kennametal?

When the application doesn't need it. If you're drilling a one-off hole in mild steel every two weeks, a basic HSS drill is fine. Kennametal tooling is an investment in productivity, not a magic charm. I've also learned not to order by phone without part numbers and a complete material spec.

In 2019, I said "we need a tougher insert." The rep heard "harder insert." Result: chipped edges on the first run. That was a communication failure, not a product failure. So don't buy Kennametal if you're not ready to give someone the material, the operation, and the machine data. With the right inputs, it's excellent. Without them, you're buying expensive scrap.

8. How do I get Kennametal support without sitting on hold?

Use the online resources first. Kennametal's website has product data, downloadable CAD models, troubleshooting guides, and the Speeds & Feeds Manager. I keep a login saved on the shop computer because I've used it more times than I can count.

When you do need a human, go through your local distributor's application engineer rather than the general phone line. I wasted two weeks in 2020 trying to get a straight answer about a boring bar vibration problem through a generic contact form. Once I talked to the local specialist, the fix was simple: reduce the overhang, raise the coolant flow, and change the insert geometry. That support is part of the value of the Kennametal brand, but you have to use it.