Metalworking fluid mixing ratios explained
Of metalworking ratios and concentrations
Metalworking chemical concentrates need to be mixed with water (remember, oil in last!) to effectively provide the manufacturers lubrication and heat removal benefits. Mixing chemical concentrate (coolant) with water is usually done with proportional mixers, e.g. proportioning pumps, or venturi mixers. These coolant mixers use ratios to mix the chemical concentrate and water. Following is how to make sense of the ratio to concentration relationship.
Metalworking sump fluids can range +/- 2% around your target concentration. However, the tighter you keep your sump concentration to the chemical concentrate manufacturers target concentration the better the coolant will work to help you meet target tolerances in finished work pieces.
HOW TO CALCULATE PERCENTAGE IF MIX RATIO IS KNOWN
Here's another example:
If your mix ratio is 4:1 or 4 parts water to 1 part solution, there are (4 + 1) or 5 parts. The mixing percentage is 20% (1 divided by 5).
HOW TO CALCULATE MIX RATIO IF PERCENTAGE IS KNOWN
Need another example?
If your percentage is 10%, take 100 - 10 (which is 90), so your mix ratio is 90:10 which can be reduced to 9:1.
Here's a list of standard metalworking fluid concentrations and ratios
| Percentage | Ratio |
|---|---|
| 2% | 49:1 |
| 3% | 32.3:1 |
| 4% | 24:1 |
| 5% | 19:1 |
| 6% | 15.6:1 |
| 7% | 13.3:1 |
| 8% | 11.5:1 |
| 9% | 10.1:1 |
| 10% | 9:1 |
| 11% | 8.1:1 |
| 12% | 7.4:1 |