HOW ARE ZINC AND MANGANESE PHOSPHATES TESTED FOR QUALITY?
The primary indicators of zinc and manganese phosphate quality are coating weight measurement and neutral salt spray resistance. Crystal size and form are important for some applications, but due to the expense of the electron microscopy necessary to make an accurate determination, this characteristic is not commonly checked on a production basis and is normally limited to first article (layout) inspection. Some specifications also include thickness requirements, but much controversy exists regarding the accuracy and methods of testing because the phosphate crystals are extremely friable and crush under even the slightest pressure. Diagnostic tests for coating integrity, torque-tension relationships and for the presence of zinc and manganese are also available. All tests performed on zinc and manganese phosphated material are destructive. WHY ARE PARKER RUST-PROOF ZINC AND MANGANESE PHOSPHATES BETTER? Phosphate coatings have been our primary business since 1918 and our dedication to cu
