What is ISO 3185 about?
ISO 3185 specifies the dimensions of normal bihexagonal head bolts, with close or large tolerance normal shank and short or medium length MJ threads, in metallic material, coated or uncoated, with strength classes less than or equal to 1 100 MPa.
ISO 3185 is applicable to the compilation of aerospace product standards.
Note: Dimensions and tolerances are expressed in millimetres. They are applicable after any coating (tolerance on shank diameter before coating is also specified for heat cured matrix coatings), but before the application of any lubricant.
Who is ISO 3185 for?
ISO 3185 on the dimensions of bihexagonal head bolts is applicable to:
- Aerospace parts manufacturers   
- Bihexagonal head bolt manufacturers
- Mechanical engineers
- Product designers
Why should you use ISO 3185?
Normal bihexagonal head bolts are easy to turn and universally accepted bolts which have become the most common shape in which bolts and nuts, as well as many other fasteners, are made.
ISO 3185 provides you with the configuration and dimensions of normal bihexagonal head bolts in a diagrammatic and tabular representation. These provisions enables you to understand the required dimensions better and help you use bihexagonal head bolts for your products safely. As a result, you will be able to reduce risk and increase operational efficiency of the end-products.
Altogether, ISO 3185 ensures delivery of high-quality inputs for overall customer satisfaction that prevents any severe safety consequences. Moreover, the strict requirements that underpin reliability for the end-product is especially important given the global nature of the industry. Keeping this in mind, you can achieve supply chain confidence and enhanced collaborative best practices in the aerospace industry.
What’s changed since the last update?
BS ISO 3185:2021 supersedes BS ISO 3185:2008, which is withdrawn. The main changes compared to the previous edition are as follows:
- Some titles of columns in Table 1 have been corrected
- The footnotes to Figure 1 and Table 1 have been clarified
