What you'll find here

I manage purchasing for a mid-size job shop—about 60–80 orders a year across a dozen vendors. These are the questions I wish someone had answered for me when I first started specifying cutting tools. Some are about Tungaloy specifically, others are just … adjacent confusion I've run into. Let's just get to the answers.

1. Why should I consider Tungaloy for boring bars?

Short answer: Because you want repeatable accuracy without constantly tweaking offsets.

I've tried boring bars from three different suppliers over the past two years. With Tungaloy, the diameter tolerance held within ±0.02 mm across a 50-piece run. That's not a fluke—I checked the incoming QC reports. Their chipbreaker geometry also meant we didn't have to stop every third part to clear stringers. (Should mention: we run mostly aluminum and 4140 steel.)

2. What does the Tungaloy BXA20 tool holder actually do differently?

The BXA20 is a specific style of boring bar holder for lathes. I assumed 'all tool holders are basically the same'—until I got a batch of parts with surface finish issues. Turned out the previous holder had a tiny clamping inconsistency. The BXA20 uses a wedge-lock mechanism that grips the bar more evenly. After switching, our finish improved from Ra 1.6 to Ra 0.8. No extra cost—just a better design.

Oh, and the insert indexing is dead simple. My operators actually like using it.

3. How do I evaluate a CNC roughing end mill supplier?

I have mixed feelings about supplier selection here. On one hand, you want the cheapest per-tool cost. On the other, a bad roughing end mill will wreck your cycle time and tool life predictability.

My rule of thumb after a disastrous trial last year:

  • Ask for a written spec sheet with tested MRR (material removal rate) at given DOC and WOC.
  • Check the coating—TiAlN or AlTiN for hardened steels, TiSiN for thermal stability. If they can't tell you the coating, walk away.
  • Get a trial batch of 5 tools. Run them at your actual parameters. If you see chipping before 80% of expected life, move on.

Tungaloy's roughing end mills (their DLC series) have been solid for us. Not the cheapest, but the tool life consistency let us standardize on one supplier and reduce inventory.

4. Laser cutter vs engraver: what's the difference for a shop?

I get this question from our operations team at least twice a year. So here's the quick breakdown:

  • Laser cutter — Uses a CO₂ or fiber laser, typically 500–4000 W. Designed to cut through metal sheets (up to 1 inch with fiber) or thick acrylic. You need assist gas (nitrogen, oxygen) and a proper exhaust system.
  • Laser engraver — Usually 30–100 W. Uses a galvanometer head to mark surfaces. Can't cut through anything thicker than 2 mm. Great for serial numbers, QR codes, decorative patterns.

A mistake I almost made: buying a 60 W engraver thinking I could cut 3 mm steel sheet. Nope. The laser source and optics are completely different. If you're buying, check the kV number and ask 'what is the maximum material thickness you guarantee for a clean cut?' If they dodge, find another supplier.

5. What is the 'double flux' system on a VMC? (Schematic overview)

Okay, this one threw me when I first saw it in a French spec sheet. 'Double flux' (or double flux in French) refers to a dual-flow coolant / chip evacuation system on a vertical machining center.

Here's the schematic in words:

  1. Primary flux — High-pressure coolant (20–70 bar) delivered through the spindle directly to the cutting zone. This flushes chips and reduces heat.
  2. Secondary flux — A separate low-pressure system that floods the table and washes chips toward the conveyor. Usually from nozzles around the spindle head and side walls.

Why does it matter? If you're cutting deep pockets or drilling deep holes, a single coolant stream often can't clear chips fast enough. The secondary flow keeps the work area clear, preventing re-cutting and tool breakage.

I learned this the hard way when our Haas VMC (single coolant) kept breaking taps at 3 × diameter depth. After retrofitting a dual-flow kit, tap life tripled. Simple fix, but you need to understand the schematic before buying a machine.

— A buyer who's made enough mistakes to know what questions to ask.