Steve Best
Well-Known Member
Hi RA1977691, that post you replied to is 8 years old. Looking at his history, Nik hasn't been around for those 8 years either.
The colour of the bolt does not tell you anything about it. It is just a surface treatment and could be heat treatment, Parkerizing or some other cosmetic coating/treatment.
Your information is 20 or 30 years out of date. Cheap bolts these days come from off-shore and are sometimes made from sub-standard steel that may be brittle if heat-treated to a hardness (which would make them black, true enough). The plain grey bolts are typically not heat treated and do bend without cracking. This is still a lot of guessing and conjecture. The answer is to buy good brand name bolts and studs in grade 8.8. Here is a chart to give you an idea of where to find that info on metric bolts:
Below is the marks on the nuts
Steve
The colour of the bolt does not tell you anything about it. It is just a surface treatment and could be heat treatment, Parkerizing or some other cosmetic coating/treatment.
Your information is 20 or 30 years out of date. Cheap bolts these days come from off-shore and are sometimes made from sub-standard steel that may be brittle if heat-treated to a hardness (which would make them black, true enough). The plain grey bolts are typically not heat treated and do bend without cracking. This is still a lot of guessing and conjecture. The answer is to buy good brand name bolts and studs in grade 8.8. Here is a chart to give you an idea of where to find that info on metric bolts:
Below is the marks on the nuts
Steve
