A shop considering minimum quantity lubrication usually has a practical reason: a part that takes too long to clean, too much fluid carried out with chips, or an operation that could run with less liquid around it. The first question is whether the lubricant can reach the cutting edge reliably. The next is whether the part still holds size and finish through a normal production run.
Evaluate MQL as a complete machining arrangement: fluid, delivery equipment, tooling, chip removal and the finished part. Tech Tool carries Oemeta MICROTOL FA 20 for minimum quantity lubrication. It is a product to review for the application, not a reason to replace flood coolant before the rest of the process has been checked.
This guide helps machinists, process engineers and buyers organize that review. It includes a trial worksheet and a consumption calculation that separates time cutting from time spent loading, indexing and waiting. Those details make a fluid quote more useful and a trial result easier to trust.
What minimum quantity lubrication changes
MQL, also called near-dry machining, supplies a small amount of lubricant to the working area rather than flooding it with recirculating fluid. Oemeta's MQL overview describes an air-oil mixture delivered through a spray system to the area between tool and workpiece. MQL still uses lubricant; it is different from machining dry.
The distinction matters when a shop compares methods. Flood delivery can supply lubrication while carrying heat and chips away in a much larger liquid flow. An MQL setup has to manage the operation with a different delivery arrangement. Turning down an existing coolant nozzle does not establish a qualified MQL process.
Unist's MQL Handbook, version 1.0.7, discusses heat management, chip behavior and tool suitability alongside fluid choice. Its useful engineering point is that the lubricant must reach the working surfaces while the process manages the heat and chips it produces. The handbook's example rates and results are not MICROTOL FA 20 settings.
Start with one operation and one defined job. A visible success on an accessible face does not prove that the same setup will reach a recessed feature or behave the same way during a long engagement. Keep the proposed change narrow enough to find out what is actually happening.
Where MICROTOL FA 20 fits
Oemeta's current U.S. MICROTOL FA 20 page lists steel, stainless steel, aluminum, gray cast iron, titanium, glass and yellow metals among its material applications. It identifies drilling, turning, milling and threading, as well as forming uses. Oemeta describes the formulation as free of mineral oil, formaldehyde, biocides and boron, with good spraying, wetting and adhesion behavior.
Use that information to begin a product discussion. Confirm the exact alloy, tool, machine and dosing equipment with the suppliers before deciding on a trial. A listed material group is not a promise for every geometry, production rate or finishing requirement within that group.
Oemeta describes favorable residue behavior and reduced cleaning effort. The downstream process still decides what is acceptable. If the next step is bonding, coating, plating, sealing or assembly, involve that process owner and retain its normal acceptance test. A clean-looking part is not proof that a cleaning step can be removed.
Request the current technical data sheet and matching SDS for the proposed supply. Agree on use instructions and equipment compatibility rather than assuming a water-mixed coolant procedure applies. The product name alone does not supply a dosing rate, air pressure or program setting.
Check how the fluid gets to each operation
Identify whether the machine will use external delivery, internal delivery through a compatible tool arrangement, or another supported method. Ask the equipment supplier how the system meters fluid, where air and fluid combine, and what happens when delivery starts and stops. Record the actual arrangement rather than relying on a generic “single-channel” or “dual-channel” label.
For an external nozzle, review the working position through the full programmed movement. A nozzle that appears well aimed at setup may be blocked by the workpiece, fixture or chip as the cut progresses. For internal delivery, confirm the machine, holder and tool passages are intended for the arrangement. Neither method is automatically the right answer for every feature.
Unist's CNC-controlled MQL example shows why operation-specific control can matter: different operations can use different delivery commands, and nozzle position remains important even with accurately metered output. Its Quantum equipment example is not a claim that Tech Tool supplies that system or that its settings apply to your machine.
Ask what confirms fluid arrival, not just a command to deliver it. Depending on the equipment, a pump signal, level alarm or flow indication may describe different parts of the system. Have the supplier explain what each signal proves and what still needs checking. Record startup delay, interruption behavior and the supported inspection procedure.
Keep delivery checks within the machine's guarding and maintenance procedures. If the setup requires changes to controls, lines, holders or safeguarding, use qualified personnel and the equipment documentation. A trial sheet should describe the approved arrangement; it should not become an improvised installation guide.
Choose fluid properties with the dosing system
A lubricant needs to work at the surface and pass through the delivery equipment consistently. Unist's MQL fluid-selection guidance identifies wetting and viscosity as important considerations. That supports reviewing the fluid and delivery system together. It does not establish a universal viscosity or flash-point requirement for MICROTOL FA 20.
Ask the dosing supplier which product properties and operating conditions it needs to review. Give it the exact product identity and current technical documents. If the machine already uses MQL, record the existing fluid, system model, line arrangement and current settings so the comparison has a clear starting point.
Keep a product change separate from a delivery change where the trial allows it. If both must change, identify the result as a comparison of two complete arrangements. Otherwise a better nozzle position or a corrected startup sequence could be credited to the new fluid alone.
Qualify heat, chips and the complete part
Use the drawing and production requirements to decide what to measure. Inspect size, finish, burrs and tool condition at agreed points. If temperature affects the measurement, use the shop's established inspection procedure and record the timing. Do not compare a warm trial part with a baseline part measured after a different wait.
Watch how the operation changes over the run, not only on the first piece. Record tool age, interruptions and workload. A short trial that stops before the normal difficult portion of tool life may tell the buyer very little about the eventual production cost.
Review chip removal with the machine and tooling suppliers. If chips accumulate or repeatedly contact the part, resolve the cause before extending the trial. Do not use extra air as an automatic cure without checking the supported delivery arrangement and the shop's exposure and containment controls.
Carry marked samples through the normal next operations. Keep cleaning, packaging and inspection conditions comparable. When a trial changes the residue left on the part, ask the next process owner what test will demonstrate acceptance. Record that result alongside the machining result.
An MQL trial worksheet that supports a decision
| Record | What to capture | Question it answers |
|---|---|---|
| Job and baseline | Alloy, drawing, tool, program, accepted output and current costs | Are we comparing the same production requirement? |
| Fluid and equipment | Exact lubricant, dosing-system identity and approved delivery arrangement | Has the proposed pairing been reviewed? |
| Delivery by operation | Start and stop behavior, settings, access and available verification signals | Does fluid arrive when and where the cut needs it? |
| Machining result | Size, finish, burrs, chip behavior and tool-life limit | Does the operation stay acceptable through a representative run? |
| Next process | Cleaning or surface test, packaging and downstream acceptance | Does the whole part route still work? |
| Consumption and cost | Measured refill volume, delivery-on time, labor, tools and accepted quantity | What does the complete arrangement cost per good part? |
Set pass conditions before cutting. Define who can change settings, who reviews an unexpected result and what ends the trial. The operator needs a clear instruction when delivery fails or a quality result moves outside the agreed limit. An unexplained change is a reason to investigate, not a reason to keep running until the trial quantity is complete.
Separate cut time from total cycle time
A rate in milliliters per hour is incomplete without saying when delivery is on. A six-minute cycle may include only two minutes of cutting. If the applicator stays on during loading or waiting, consumption will differ from a calculation based only on cut time.
Illustrative arithmetic, not a recommended setting or customer result: suppose an agreed trial setting delivers 30 mL per delivery-on hour. Each part requires two minutes of delivery, and the run makes 600 pieces. Delivery time is 600 × 2 ÷ 60 = 20 hours. The nominal delivered volume is 30 × 20 = 600 mL, or 0.6 L.
If the same delivery remains on for the entire six-minute cycle, the nominal volume becomes 30 × 60 = 1,800 mL, or 1.8 L. The calculation shows why the control sequence belongs in the consumption record. It does not say either amount is appropriate for your job.
Compare the calculation with measured replenishment over the run. Account for priming, setup use, line contents, spills and any other recorded use. If those differ, investigate the difference instead of changing the number until it fits the expected result. Where the equipment supports separate delivery settings by operation, calculate each period separately and total them.
Multiply measured liters used by the actual price per liter to obtain the fluid-cost line. Divide by accepted parts for the fluid cost per accepted piece. Keep that figure separate from total machining cost so a low fluid figure cannot hide a slower cycle or more rejects.
Compare the complete cost, not circulating flow
Flood flow through a nozzle is not the same as fluid purchased and consumed. Much of a recirculating supply returns to the system. Comparing an MQL consumption rate with a flood circulation rate as though both are purchases produces a misleading savings claim.
Use actual replenishment and the same cost boundary for both arrangements. Include relevant tool use, labor, quality loss, cleaning, chip handling and delivery-equipment costs. Record which maintenance tasks change and which remain. Include installation and qualification costs when deciding whether a change is worth extending.
A useful trial can show that MQL fits one operation while flood remains appropriate elsewhere. Keep that result. A selective change is easier to support than a machine-wide claim the evidence does not cover. Purchasing can then quote the quantity and delivery arrangement for the qualified job rather than buying against a broad promise.
Keep the exposure review in the trial
Small fluid consumption does not establish zero airborne exposure. OSHA's metalworking-fluid exposure guidance calls for reviewing SDS information, delivery systems, guards and exhaust controls. Review those measures for the actual process with the site's responsible personnel; a supplier's clean-process description does not replace the review.
Have a clear route for reporting delivery problems, visible escape from the enclosure or symptoms associated with the work. Do not remove existing controls based on an assumption that near-dry means harmless. Keep this evaluation separate from a claim that the fluid will improve the finish or reduce consumption.
Five checks before extending an MQL trial
- Confirm the exact MQL fluid and delivery equipment for the alloy and operation.
- Verify fluid arrival through the full operation, including startup and interruptions.
- Track size, finish, chip removal and tool condition over a representative run.
- Check the normal cleaning and downstream acceptance requirements on marked samples.
- Compare measured consumption and complete relevant costs per accepted part.
Questions shops ask about minimum quantity lubrication
Is MQL the same as dry machining?
No. MQL supplies lubricant in a small quantity; dry machining does not. The fluid and its delivery behavior remain part of the MQL process that needs qualification.
Can we use one setting for every operation?
Do not assume so. Review access, tooling, engagement and the equipment's supported controls for each operation. Establish the settings with the suppliers and retain them with the program or setup record.
Does the MICROTOL FA 20 material list approve our specific job?
It identifies application groups for a product discussion. Confirm the exact alloy, feature, tool and delivery arrangement, then test the required production and downstream results. A group listing is not a finished-job approval.
Can we eliminate washing if the part looks dry?
Only after the downstream process has been reviewed and its acceptance requirements demonstrated. Keep the established cleaning route during the initial comparison unless the agreed trial explicitly tests a different route.
Why does refill volume exceed the calculated delivery volume?
Review actual delivery-on time, priming, setup, spills and the equipment's measurement method. Ask the dosing supplier what the indication measures. Use measured replenishment for purchasing while resolving the difference.
Bring Tech Tool the operation you want to change
For a MICROTOL FA 20 review, contact Tech Tool with the alloy, operation and dosing-system details. Include the current fluid, tooling, cycle and cut times, the reason for considering MQL, and the cleaning or finishing steps that follow.
Tech Tool can help obtain current Oemeta documentation and organize the product discussion with the relevant suppliers. A defined trial gives the next order a clear purpose: supplying a fluid for a process the shop has evaluated, with the measurements needed to judge its value.
