Royco 638 is or was manufactured by Royco Lubricants. The product offered by BlueSky Lubricants is a replacement product of similar quality and performance as a synthetic compressor oil. If you have any questions concerning BlueSky Lubricants’ alternative to Royco products, please contact us by our Toll Free Phone Number 1-855-899-7467.
PAO Synthetic, Extreme Pressure Gear Lubricant. Below is the BlueSky replacement