AS 3566.2:2002 pdf free.Self-drilling screws for the building and construction industries Part 2: Corrosion resistance requirements.
5 REQUIREMENTS FOR CORROSION RESISTANCE
5.1 Class 1
Class I corrosion resistant screws shall comply with one of the following requirements:
(a) Accelerated testing When Class 1 corrosion resistant self-drilling screws are prepared in accordance with Appendix A and tested in a neutral salt spray in accordance with AS 233 1.3.1 for 72 h red rust shall not be present over more than 5 percent of the significant areas of the screws and there shall be no blistering of the coating.
(b) Zinc and zinc-till coated screws The metallic coating of zinc and zinc—tin coated Class 1 corrosion resistant screws shall be in accordance with Table 2. The local thickness of the metallic coating shall be determined in accordance with AS 2331. 1 .3 or AS 2331 .1 .4 and the minimum local coating thickness shall be determined from three local thickness measurements made on the reference surface shown in Figure 1.
5.2 Class 2
Class 2 corrosion resistant screws shall comply with one of the following requirements:
(a) Accelerated testing When Class 2 corrosion resistant self-drilling screws are prepared in accordance with Appendix A and tested as follows red rust shall not be present over more than 5 percent of the significant surfaces of the screws and there shall be no blistering of the coating:
(i) In a neutral salt spray in accordance with AS 233 1.3. 1 for 240 h.
(ii) In a condensing atmosphere containing sulfur dioxide at level KFW 2.OS in accordance with DIN 50018 for 5 cycles.
(iii) The assessment of the level of rusting shall be conducted visually so that no doubt can exist that corrosion of the steel substrate is well established.
(b) Zinc and zinc-tin-coated screws The metallic coating of zinc and zinc-tin coated Class 2 corrosion resistant screws shall be in accordance with Table 2. The local thickness of the metallic coating shall be determined in accordance with AS 2331 . 1 .3 or AS 233 1.1.4 and the minimum local coating thickness shall be determined from three local thickness measurements made on the reference surface shown in Figure 1.AS 3566.2 pdf download.