It specifies that coatings must not cause the thread dimensions to exceed the "zero line" for bolt threads or fail to reach it for nut threads .
The dimensions and tolerances of the fasteners shall be in accordance with the relevant standards, such as DIN 13 and DIN 14. din 267 part 9 pdf
If you are designing a high-temperature bolted joint: It specifies that coatings must not cause the
DIN 267 Part 9 specifically deals with the requirements for fastener coatings and surface treatments. The standard provides guidelines for the application of coatings and surface treatments to fasteners, including electroplating, hot-dip galvanizing, and other methods. The objective of Part 9 is to ensure that fasteners have adequate corrosion resistance and durability, which is essential for their performance and longevity. din 267 part 9 pdf