Issues with fasteners when used outdoors
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This post was last edited by FMSD on 2016-12-28 at 14:27. Should bolts, nuts, and washers used in outdoor environments be selected with an oxidized or galvanized passivation coating? Fasteners that have not undergone surface treatment are not suitable for use in outdoor environments, right? The surfaces of many standard fasteners are left untreated. For example: Bolts of grades A and B have their surfaces oxidized, while those of grade C are not treated. Hex nuts of type 2 are oxidized, whereas those of type 1 are not treated. I think that using bolts in accordance with GB/T 5782—2000, along with hex nuts of type 2 per GB/T 6175—2000, should allow for use in outdoor conditions. However, the washers listed below do not have any surface treatment – that’s really frustrating. Flat washers – Class C (GB/T 95—2002); Large washers – Class A (GB/T 96.1—2002). Flat washers – Class A (GB/T 97.1—2002); Flanged flat washers – Class A (GB/T 97.2—2002). Large washers – Class C (GB/T 96.2—2002); Extra-large washers – Class C (GB/T 5287—2002). By default, these are not treated in any way. When the order quantity is small, it’s acceptable to use washers made of steel structures, right? Is it a bit weird?
It depends on whether the local environment of the equipment being used is harsh.
Comprehensive, accurate, genuine, and effective operations as well as material selection all stem from practice; therefore, there are bound to be more or less omissions in the formulation of standards. Abroad, it is specialized institutions with true experts who develop the standards, while here it is the manufacturers who participate in standard development, which leads to significant bias.
Even if the conditions are not harsh, untreated carbon steel will rust very quickly.
Rusting indicates that the conditions are quite harsh.
Carbon steel bolts are generally not treated, right? Fasteners made of alloy steel generally require bluing treatment.
It depends on the execution standard; different standards result in different default handling methods