Tools
Shim stack calculator.
Measured a gap? Enter it in millimetres or inches and get the fewest colour-coded Polymex® shims that make it up, ready to pick from stock by colour.
- Thinnest Polymex® film
- 12 µm
- Shims in a stack
- Up to 12
Shim stack calculator
Make up any gap with Polymex® shims.
Enter the gap you measured. The calculator finds the fewest shims that make it up, then the fewest colours, so the stack is quick to pick and easy to check.
Enter the gap you measured to see the stack of shims that makes it up.
How to use it
From a measured gap to a fitted stack.
- 01
Measure the gap
Measure at the tightest point with feeler gauges, a micrometer or a depth gauge, in millimetres or inches.
- 02
Enter it and choose the rule
Type the measurement and pick the unit. Keep "Not exceed the gap" for a stack that must fit, or choose "Be nearest, either side" when a slightly thicker stack is acceptable.
- 03
Pick the shims by colour
Each Polymex® thickness has its own colour, so the stack can be picked from stock by colour alone. Compare the other stacks offered if you would rather use fewer shims or a single colour.
- 04
Check, then fit
Thicknesses are nominal. Check the finished stack with a feeler gauge or micrometer before fitting.
Colour-coded Polymex® shims
The colour is the thickness.
PSG invented colour-coded plastic shims. Every Polymex® thickness has its own colour, from the 0.012 mm Clear film to the 3.000 mm Black, so the right shim is obvious on the shop floor and a stack can be checked at a glance. Polymex® is non-hygroscopic, oil-resistant, corrosion-resistant and non-conductive.
- Clear 0.012 mm
- Purple 0.025 mm
- Pink 0.037 mm
- Blue 0.050 mm
- Black 0.065 mm
- Green 0.075 mm
- Amber 0.100 mm
- Brown 0.125 mm
- Clear 0.150 mm
- P. Blue 0.175 mm
- Hazy 0.190 mm
- T. Blue 0.200 mm
- Silver 0.225 mm
- White 0.250 mm
- D. Green 0.300 mm
- Natural 0.350 mm
- Red 0.375 mm
- Yellow 0.500 mm
- Hazy 0.500 mm
- L. Grey 0.625 mm
- Blue 0.750 mm
- Tan 1.000 mm
- C. Grey 1.250 mm
- Cream 1.500 mm
- Natural 2.000 mm
- Black 3.000 mm
Colours on screen are indicative. Ask for a physical Polymex® swatch for exact matching.
Common questions
Shim stacks, answered.
How do I measure the gap?
Measure at the tightest point, with the parts held where they will sit when fitted. Feeler gauges, a micrometer or a depth gauge all work. If the gap may taper, take more than one reading and use the smallest for a stack that has to fit.
Why does the calculator not exceed the gap?
A stack thicker than the gap will not go in without forcing the parts, so by default the calculator only offers stacks at or under the gap. Choose "Be nearest, either side" when your design allows a slightly thicker stack; the calculator then also shows the closest stack that fits.
Can I mix colours in one stack?
Yes. Most gaps are made up from two or three thicknesses, and the calculator lists each colour with how many you need. Because every Polymex® thickness has its own colour, a mixed stack can still be checked by eye.
What if my gap is thinner than 0.012 mm, or thicker than the calculator allows?
The thinnest Polymex® film is the 0.012 mm (0.0005 in) Clear grade, and the calculator builds stacks of up to twelve shims, to 36 mm with the 3.000 mm Black. For anything finer or larger, ask our team: a custom shim, a spacer or a different material may suit the job better.
Are the thicknesses exact?
They are the nominal thicknesses from the Polymex® colour chart. Check the finished stack with a feeler gauge or micrometer before fitting, and ask our team about tolerances for your application.
Why can millimetres and inches give slightly different stacks?
Each Polymex® grade is published in both units, and each is rounded on its own: Yellow is 0.500 mm and 0.020 in, which are 0.008 mm apart. The calculator works in the unit you enter, against the published thicknesses in that unit, so an answer in inches matches the inch chart.
Can PSG cut custom shims and gaskets?
Yes. We cut shims and gaskets to your drawing in-house, by die cutting, laser and water jet. See custom shims and custom gaskets, or send us your drawing.
Need shims cut to your drawing?
Send us your drawing or your measurements and our technical team will come back to you with a quotation.
