Refractometer

Why Regular Coolant Testing Matters In deep hole drilling, the coolant does double duty: it lubricates the cutting zone and flushes chips out of the bore. Contaminated or degraded coolant fails at both tasks. I test the coolant weekly using a standard procedure that takes about 5 minutes per machine. The time is well spent when it prevents a coolant-related tool failure or part rejection. I have traced problems including poor surface finish, accelerated tool wear, and bacterial stink all to coolant that had drifted outside specification. In each case, the weekly test would have caught the issue days or weeks before it affected production. ...

I have watched more than one shop chase tool breakage for a week only to discover the coolant was running at half the recommended concentration. Coolant concentration is the kind of variable that does not announce itself. It drifts slowly, a tenth of a point at a time, until one day nothing works right anymore. Here is how I measure it, what the numbers should be, and what to do when they are wrong. ...