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Shock oil weight to cSt converter

Convert silicone shock oil between weight and centistokes.

Shock oil
Weight and centistokes, on the chart for the oil in your hand.

The chart most kit manuals and forum posts quote. The safe guess when you are not sure.

350cSt

Losi / TLR

Published figures

Anything between two of these is worked out along the line between them.

WeightViscosity
10 WT100 cSt
15 WT150 cSt
20 WT200 cSt
25 WT275 cSt
30 WT350 cSt
35 WT425 cSt
40 WT500 cSt
45 WT575 cSt
50 WT650 cSt
55 WT725 cSt
60 WT800 cSt
70 WT900 cSt
80 WT1000 cSt

Why two numbers for the same oil

Centistokes (cSt) is a measured viscosity: it means the same thing whoever filled the bottle. Weight (WT) is a label each maker chose for themselves, with no standard behind it — which is why the converter asks whose oil you have before it answers. Losi 30 WT and Associated 30 WT are not the same oil, and the gap is worth about two and a half points on the label.

It is not a straight multiplication either. Thin oils run near 10 cSt per point of weight and thicker ones nearer 13, so the converter follows each brand's published figures and works out anything in between along the line between them.

How much to trust it

These charts were measured and circulated by racers rather than certified by manufacturers, and two bottles of the same label can differ by a few percent anyway. So treat a converted figure as where to start a rebuild, not a specification: read the cSt off the bottle when it is printed there, and stick to one brand in your pit box so that what you learn about 400 cSt keeps meaning the same thing.

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