Supported ISO and DIN standards
Fasteners are a triumph of standardization. You can buy a bolt in Japan and fit it to a nut from France because they all follow the same ISO standard.
We start at the source
When we add a fastener to our library, we start by buying the PDF of the standard. We don’t grab a list of dimensions from a random Google result. By using the standard, we make sure all dimensions are absolutely correct.
We then extract all size and shape data from the standard and turn it into software that creates fastener models. And because the software is in version control, it keeps getting better and more robust.
We only use active standards
Because we always buy the standard PDF and you cannot buy withdrawn standards, we only support active standards.
Many popular DIN standards were withdrawn in the 80’s and the 90’s, but people still refer to them. We only refer to the replacement ISO standards in our shop and in the filenames. But to make things easier, we add the withdrawn DIN standard in brackets in the shop and we include two custom properties (DIN and DIN withdrawn) in each part.
If you want to learn more about withdrawn DIN standards and their ISO replacement, check out this explainer PDF on reyher.de and the list of DIN standards on Wikipedia. Also check out our article Why we’re still fighting for perfect fasteners in CAD on engineering.com.
The most notable differences are the head shapes of countersunk ISO 10642 bolts that differ from the old DIN 7991 sizes and the wrench sizes of M10, M12, M14 and M22 hexagon head bolts.
About materials and coatings
Most standards include preferred materials and some standards also talk about coatings/finishes. But in practice, what people use and what companies sell is rather different. So we do our best to include materials and finishes that are used in practice. If there is a material you want to add, you can always copy a folder, modify the filenames and custom properties. We can also do that for you; see our Customization services.
What the standards don’t specify
Fastener standards are written for manufacturers, not for engineers. They specify head shapes, preferred lengths and tolerances. But they often leave the under-head shape undefined and the longer lengths can be chosen by the manufacturer.
Our models are made for engineers. That means we often have to estimate the under-head shape and we can only include the lengths that are specified. We use a 6mm shaft diameter for an M6 bolt, not the exact toleranced size, and we use the maximum head size when one is specified to be on the safe side.