New Release of Spring Calculator Professional - April 2026
New numbering, new features and more - a run-down on what's changed
As some of you will have already seen from the auto-update notification, we put a new version of SCP live yesterday (27th April) after demonstrating it to visitors at the Wire Dusseldorf fair two weeks ago. We had time to squeeze in one or two last-minute changes based on feedback we received, showing the value of working directly with our customers – more on the Working Group later!
Version 26 - what's that all about??
One thing that many of you will notice is what seems a strange jump in the numbering system, from 2.9 to 26! There’s a good reason behind this, I promise. We tend to put out a major new release of our software every 10-15 years; some of you will remember the old “Version 7” software which was technically called “IST Spring Design & Validation”, and was superseded by the first release of Spring Calculator Professional in 2011. These milestones tend to involve a major re-write, generally based on new technology. We didn’t want to jump to version 3.0 of SCP, because this is more of an incremental update, so we decided to pin the version numbers to the date. So we have 26.1 representing the first release of 2026. This also helps identify how old a particular version is.
So what are the changes in this release, and what made us choose them?
Firstly, this release is the first one driven by our software Working Group, which meets a couple of times a year online and is made up of people like you, users of our software. We wanted to be truly immersed in what people who use SCP in their faily lives actually need from it. So we came up with a long list of potential improvements and new features, created a voting system and an algorithm to decide how to prioritise them, and this is the result! If anyone else wants to get involved in the Working Group, please contact john@ist.org.uk. You don’t have to be a member, just someone with an interest in our software.
One of the main changes is an improvement in the specification of legs for torsion springs. You can now give a bend radius for both internal and external radial legs. This sounds like a fairly trivial change, but it actually has quite a few knock-on effects. Firstly, you can make the drawings much more accurate, which is always a benefit. It allows us to calculate more of the tolerances from DIN 2194, so you’ll now see tolerances on leg length, bend radius and bend angle. And if the bends are tight enough, there is an increase in stress which becomes more important than the main body stress.
You can also specify the position on the leg where the load is applied – previously you were forced to enter just the active leg length, which was fine for calculations but a little confusing.
The new popup window allowing additional leg specifications.
More in-depth tolerance calculations.
Visualisation of the specified bend radius values.
Other changes
There are a number of other things we’ve added and improved, as well as a few bugfixes. If you want a full list, check out the release notes on our help site.
We’ve added a numerical life prediction to the compression spring Goodman diagram. This is something we’ve historically resisted because of the danger of relying on the results too much, but it was something that was definitely requested! Our advice is to be aware of the limitations of statistical modelling and extrapolation, and always do testing on the real component if life is critical!
As well as the leg bend radius, you can now specify a radius for the centre section of double torsion springs. This doesn’t affect the calculations at all, but again makes the design look more realistic.
3D CAD model exports have been available for a while, but we’ve had reports that the compatibility could be better – the STP files produced work fine in some software, but not as universally as we’d like. Hopefully this problem is fixed now, as we’ve made significant improvements to the structure of the STP file export. Let us know how you get on! It’s also worth being aware that if you do have problems still, the IGES export is generally more reliable, even if it’s not the format most people prefer.
There’s a couple of tweaks to the extension spring drawing – the dimension placement for D-loops is properly placed and the hook gap value you can enter is reflected on the drawing.
You can now specify a new type of wave springs – with shim (flat) ends. The drawing is also slightly improved and more realistic for standard multi-turn springs.
Sounds great - how do I get the new version?
If you have an active maintenance contract, you’re eligible for a free upgrade. If this isn’t shown automatically in the software (maybe you need to turn on the version check in the Options window, or maybe your firewall doesn’t allow the online check), you can download it manually from this link:Â https://files.ist.org.uk/scp/scpv2/scpsetup_26.1.0.0.exe
If you’re not in maintenance, contact us for a quote.