Sherwin Penetrant Classification System

Penetrants

Type 1
Type 2

Fluorescent Dye
Visible (Red) Dye

Removal
Method
Method A
Method B
Method C
Method D

Water Washable
Post Emulsifiable, lipophilic (oil base)
Solvent
Post Emulsifiable, hydrophilic (water base)

Removers
Class 1
Class 2
Class 3

Halogenated (non-flammable)
Nonhalogenated (flammable)
Special Application

Developers

Form a
Form b
Form c
Form d
Form e
Form f

Dry Powder
Water Soluble
Water Suspendable
Nonaqueous Type 1 Fluorescent (solvent based)
Nonaqueous Type 2 Visible (solvent based)
Special Application

Fluorescent Sensitivity*
Level 1/2
Level 1
Level 2
Level 3
Level 4

Ultra Low
Low
Medium
High
Ultra High

*No sensitivity level classification exists for Type 2 Visible Penetrants

Specifications: The current specification, AMS-2644 and its QPL-AMS-2644-1, establish the penetrant system classification scheme. The scheme ranks fluorescent penetrants in terms of their sensitivity and removal properties. It also classifies developers and removers. Various classes of penetrants are approved for different inspection requirements. Penetrant users should assure that inspection procedures meet production requirements.

Consultation: It is important that a penetrant system match production requirements, not only to assure that specifications are met, but also to assure that sensitivity levels and inspection methods meet inspection criteria. Some applications have very stringent criteria calling for the highest sensitivity, while others accept lower levels of sensitivity. When penetrant systems are not appropriately matched to inspection criteria, unnecessarily high penetrant materials costs as well as the unnecessary rejection of parts can result. Or worse, parts can be accepted that otherwise should have been rejected, leading to parts failure, or recall. Sherwin Incorporated welcomes the opportunity to help users choose the appropriate combination of penetrant materials.