MR 691 F is a water-removable fluorescent penetrant classified as Type I and developed with the requirements of the automotive industry in mind. The product provides yellow fluorescent indication that clearly shows surface defects in metals and is suitable for use over the temperature range +10 °C to +50 °C. The carrier medium is glycol and the product meets several international standards for penetrant testing.

Key features and benefits

• Water-removable penetrant (Type I) that makes the cleaning process easier and safer.

• Sensitivity level 1 according to EN ISO 3452-2 (low requirement for defect detection) – adapted where small, critical cracks must be detected but sensitivity requirements are not extremely high.

• Yellow fluorescent indication that is visible under UV light.

• Carrier medium glycol — provides good flow and wetting on metal surfaces.

• Certified according to several standards: EN ISO 3452-2, ASTM E165, RCC-M and VDA236-150.

• Minimum shelf life of approximately 3 years when stored correctly.

Technical specifications

• Type: Penetrant Type I (fluorescent)

• Sensitivity class: level 1

• Indication color: yellow fluorescent under UV light

• Carrier medium: glycol

• Temperature for use: approx. +10 °C to +50 °C

• Approvals / standards: EN ISO 3452-2, ASTM E165, RCC-M, VDA236-150

• Delivery forms: bulk containers (5 L, 30 L, 200 L, 1000 L)

• Minimum shelf life: 3 years at recommended storage temperature

Areas of application

• Penetrant testing in the automotive industry where components must be inspected for surface cracks and defects with fluorescent indication.

• Production lines or maintenance workshops where water-removable penetrants are preferred over solvent-based ones for easier cleaning and better environmental conditions.

• When inspection occurs under UV light for improved contrast and visibility of indications.

• For metal components — suitability for plastic or ceramic should be tested before use.