Kennametal TX Drill Speeds and Feeds for Aluminum, Plus Kennametal Lathe Tools: A TCO Guide

Short answer: start at 650 SFM and 0.010 IPR

For most 6061-T6 aluminum jobs, a 3/8 inch Kennametal TX drill should start around 650 SFM and 0.010 inches per revolution. I know that feed sounds high if you are used to babying a drill. That is exactly the problem. Aluminum needs a chip thick enough that the cutting edge cuts instead of rubbing. When I am triaging a rush order, I do not drop the feed to feel safe. I raise the feed until the drill stops squealing.

This is not a number I picked from a marketing flyer. After coordinating 200+ urgent tooling orders, the first thing I ask on a panic job is not What’s the best tool? It’s What’s the total cost per good part? The insert price is the least meaningful number on the job card.

Why I can say this without seeing your machine

My role is tooling coordinator at a contract machining shop. Emergency jobs are not an interruption for us; they are the normal rhythm. We do same-day turnarounds for aerospace suppliers, energy equipment shops, and maintenance teams that need parts Thursday night for Friday morning. In March 2024, a client called at 7 pm with 120 aluminum plates waiting on a drilling operation. The holes had spiral marks that would fail final inspection, and the tooling lead time from any catalog was three weeks.

We swapped in a Kennametal TX drill, but the real fix was not the brand stamped on the shank. I reduced their speed from around 700 SFM to about 650 SFM, and I doubled the feed from 0.005 to 0.010 IPR. The spiral marks disappeared, the drill stopped squealing, and the batch finished before the deadline. That moment is when I stopped thinking in tool price and started thinking in cost per hole.

Aluminum tooling is a total cost game

The cheapest drill wins in the purchasing meeting and loses on the shop floor. Let me rephrase that: it loses on the shop floor when you add machine time, operator time, scrapped parts, and the cost of expediting a replacement. A $5 discount per drill means nothing if the job has to stop for a tool change at 11 pm.

A few years ago, I approved a batch of budget drills to save money on a large aluminum order. They were around $18 each versus $26 for a Kennametal TX. In that setup they averaged twelve holes before the corners chipped. The spindle stopped, the operator waited, and every tool change risked a scratch on a finished surface. The actual cost per hole was higher than if we had bought the more expensive drill that lasted ninety holes. Since that project, I calculate cost per hole before I argue about price.

Aluminum also builds up on the edge like peanut butter on a warm knife. A feed rate that is too low makes the built-up edge worse, because the tool pushes the material instead of shearing it. That is why the speed-and-feed dialog matters more than brand loyalty.

Kennametal TX drill speeds and feeds for aluminum: starting points

Here are starting points I use for 6061-T6 or similar wrought alloys in a rigid CNC setup with through-tool coolant:

• 1/4 inch TX drill: 650 to 750 SFM, 0.004 to 0.006 IPR
• 3/8 inch TX drill: 650 to 750 SFM, 0.008 to 0.012 IPR
• 1/2 inch TX drill: 600 to 700 SFM, 0.010 to 0.014 IPR

Watch the spindle load and the hole finish. If the drill squeals or the corners wear fast, increase the feed before you drop the speed. If the hole edges build up a big burr, check the point geometry and the holder runout before you change the program.

Lathe tools: Kennametal lathe tools should be chosen by geometry, not by habit

On the turning side, the most common question I get is about Kennametal lathe tools. In an emergency, people want to know which insert to run for aluminum, so let me make it simple. Pick a positive rake insert with a sharp, polished edge. A steel cutting insert with a tough chip breaker is the wrong first choice for aluminum, because it creates pressure and built-up edge.

I often reach for Kennametal K68 for aluminum finishing. It is an uncoated carbide grade designed for non-ferrous materials, and it has the edge sharpness that prevents aluminum from sticking. On lathe tools, the holder must also be clean and rigid. I have seen operators blame a new insert when the real culprit was a worn insert seat and a loose clamp screw. In a rush, check the mechanical condition before changing the cutting data.

Use the same total cost logic on inserts. If an insert costs twice as much but removes metal at twice the rate, it is probably cheaper. Work out the arithmetic with your hourly machine rate. At $100 per hour, saving ten minutes of turning on a fifty-part job saves more than $800 of machine time. That makes a $10 price difference between inserts irrelevant.

What I would do on a 24-hour job

If the deadline is tomorrow, do not start by testing six different tools. Start with the most likely setup, run one part, measure the hole or surface finish, and then adjust the feed. My routine looks like this: check the holder runout, confirm the coolant is aimed at the cut, set the starting speed and feed from the ranges above, then take one test cut and push the feed up by 10% each good part until the tool shows wear.

That is the opposite of what most operators do under pressure. They slow the machine down to be safe. Instead, reduce the number of operations and make sure the chip is thick enough to leave the cut zone. The goal is not maximum tool life. The goal is enough tool life to finish the batch without an unplanned stop.

Boundary conditions and the caveat you should expect

These recommendations were accurate as of January 2025, based on the machines and fixtures I support. They will change with your spindle, coolant pressure, and workholding. For 7075-T6, I start about 10% lower on speed. For high-silicon cast aluminum, such as 390, a carbide edge will not last; consider PCD or a grade designed for abrasive alloys. These numbers also assume a flat entry surface and good hole roundness. If you are drilling through a curved surface or an interrupted cut, peck more and expect shorter tool life.

Do not treat my starting points as a replacement for Kennametal’s official machining data. When you have time, pull the product-specific speed and feed table from their website. What I am giving you is a fast, field-tested way to get close when the clock is ticking. Tooling performance changes too fast to trust anyone who says always and never.