How I Stopped Wasting $890 on Kennametal Tool Orders: A 5-Step Pre-Check List

If you're ordering Kennametal inserts or tool holders, you've probably made at least one of the mistakes I'm about to describe. I've made most of them. The first one cost me $890 in wasted material and a week of production delay. The second was a $450 embarrassment that I still cringe about.

I handle specialty tooling orders for a mid-size CNC shop, and for the past three years (since late 2022), I've been documenting every significant error I've made or caught. So far, that list has 47 entries. This checklist is what survived the cut—the five things I check before hitting "submit" on every Kennametal order. It's saved us roughly $3,200 in preventable rework over the past 18 months.

Here's the exact process I use, step by step.

Step 1: Match the Grade to the Material, Not Just the Part Number

This sounds obvious, but it's the most common error I've documented. You'll grab a part number from your Kennametal tool library (we use their online catalog extensively), and if the number looks right, you order it. The problem is that the same holder or drill body can accept inserts in multiple grades, and the wrong grade might still fit—it just won't cut properly.

I learned this the hard way in September 2022. I ordered a Kennametal K68 insert for a 316 stainless job when the print called for KC720. The insert seated perfectly. It ran for maybe 20 parts before the edge chipped. $320 worth of inserts, down the drain, plus the scrap parts.

Here's what I do now: I create a quick reference card for our most common materials. For example:

• Steel (general): KC5410 or K68
• Stainless steel (316): KC720
• Cast iron: K68
• Aluminum: A specific uncoated grade (check the library)

I tape this to the wall next to the ordering terminal. It seems simple, but before I did this, the 'fit check' was all anyone did. Now, the 'grade check' comes first. Check point: Does the Kennametal grade number match our standard for this specific material, or is there a documented note on the job?

Step 2: Verify the Insert Geometry Against the Actual Operation

The part number might be right. The grade might be right. But the geometry—the chipbreaker, the nose radius, the relief angle—can still be wrong for the operation. This is the step most people skip (I did, repeatedly).

I once ordered Kennametal inserts for a finishing pass on a fairly simple steel part. I checked the grade (K68, correct). I checked the size (correct). What I missed was the nose radius. The print called for a 0.016" radius. The inserts I ordered had a 0.031" radius. Everything else was fine. The surface finish was a disaster. That was the $450 embarrassment I mentioned earlier—plus a 2-day delay while we expedited the right inserts.

(The surprise wasn't that the finish was bad, honestly. It was that the operation itself—finishing—collapsed completely. A finishing tool with the wrong radius isn't just 'less good'; it's often unusable.)

Check point: Does the Kennametal part number's geometry (nose radius, chipbreaker style) match the specific operation (roughing, semi-finishing, finishing) and the surface finish requirement on the print?

Step 3: Do the Feeds and Speeds Sanity Check (from the Library)

This step changed for me after Q1 2024. We started using Kennametal's online feeds and speeds database more aggressively (their tool library on the web includes recommended starting parameters). But I made the mistake of trusting the library's generic recommendation without adjusting for our specific setup: an older machine with slightly less rigidity.

The numbers looked great on paper. The insert was a KC5410, right grade for the steel. The geometry was correct. I ordered based on the library's suggested speed. First part, the insert lasted 8 parts before failure. The recommended speed was for a 'new' machine with high rigidity. Ours is a 'solid but not new' 2015 model.

What my gut told me ("reduce by 15%") was overridden by the data on the screen ("325 sfm"). I learned to trust the gut check, especially on older machines. Now, I use the library data as a starting point, then apply a 'machine factor'—usually 10-15% reduction for older equipment unless we have successful run data.

Check point: Have we run this exact Kennametal grade/geometry combo on our specific machine before? If not, is the recommended speed adjusted for our machine's rigidity and power? (If you don't know, add a note to start 15% lower and test.)

Step 4: Cross-Reference the Holder's Pocket Condition

This one is almost never on anyone's checklist, and it's cost us. A Kennametal tool holder is a precision instrument. The pocket—where the insert sits—needs to be clean, undamaged, and the correct size for the new insert. I caught this error because I was looking at the wrong part of the system.

In late 2023, I ordered a batch of inserts for a Kennametal boring bar we had in stock. The part numbers matched. The grade was perfect. The inserts seated beautifully. On the first cut, the insert shifted. Turns out the pocket of the boring bar had a small burr from a previous crash (which I hadn't known about, as I was ordering for a machine I didn't usually run). The new insert couldn't seat properly.

This is where a checklist really shines. I now add a step: physically check the holder pocket before the order is even placed, if possible. If you're ordering for a remote location, call the operator and ask. Their answer might surprise you. (One operator told me, "I've been shimming that holder for two years." I never would have known.)

Check point: Is the tool holder's insert pocket clean, free of burrs, and within spec for the new insert geometry?

Step 5: Check the Coating—Not Just the Grade

This is the most recent addition to my checklist (added after Q3 2024). Kennametal often offers the same base grade with different coatings, or the same coating applied to different substrates. The part numbers can look nearly identical. I assumed 'cermet' vs 'coated carbide' was a detail I'd catch. I didn't.

On a production run of 500 parts, I ordered a coated grade when the job history specifically called for an uncoated cermet for that particular finish. The coated insert left a visible edge pattern that didn't meet the customer's aesthetic requirement. (The spec said 'no visible tool marks,' which the coated insert produced.) The run was 300 parts in before we noticed. Rework time: 3 days, plus the cost of the new, correct inserts. I don't have an exact dollar figure for that one, but it was expensive.

Check point: Does the job history or the engineering print specify a coating requirement (or explicitly state 'uncoated')? Does the Kennametal part number you are ordering match that specification?

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This list is not exhaustive, but it covers about 80% of the preventable errors I've documented. A few other things I always keep in mind:

• Quantity creep: The tool library might show a standard package quantity. Double-check if you need 10 or 100. I once ordered 100 inserts instead of 10 (a simple click-error on the quantity field). The order shipped before I could catch it. (USPS rates to return, as of January 2025, are $0.73 for a first-class letter, but a box of inserts is a different story.)
• The 'new guy' factor: If someone new is covering the order, the checklist is non-negotiable. I made the most errors in my first year (2017). Now, this list is part of our team's onboarding.
• Don't trust the 'last time' reference: The part number you ordered last month might have been superseded, or the coating might have changed. Check the current Kennametal library entry, even for repeat orders. (Granted, this takes 30 seconds, but it's saved me twice.)

If you follow these five steps, you'll catch the errors that most people miss. Industry has changed since 2020—tooling data is more available than ever, but the fundamentals of checking geometry, grade, and the condition of the holder haven't. I've made the mistakes so you don't have to.