Currently out of stock with supplier until late JULY 2025
HM-604 is a high sensitivity, solvent or water-washable fluorescent penetrant. It has been accepted and used by major aerospace firms - airframes, turbine engine, and missile - for several years. Approved under MIL-I-25135 and AMS-2644, HM-604 qualified to the stricter requirements of MIL-I-25135-D without modification. Sherwin Incorporated recognized early the need for high flash point, highly stable, nonvolatile, and low toxicity penetrant.
