SH3 Tread Code
SH
Service category — which machineSubterranean haulage
Underground haulage, where the tyre works in a confined space and heat has nowhere to go.
3
Tread type and depthRegular Tread
The standard depth of the series, and the baseline the deeper grades are measured against.
ETRTO
The same code under the other standardRegular Tread
ETRTO Standards Manual 2026 lists SH-3 as a regular tread. Using these codes at all is left to the individual tyre maker, so a tyre may be marked to ETRTO, to TRA, or to neither.
TKPH
What the code does not tell youNothing about load, or heat
A tread code says which machine and how much rubber. What the tyre can carry comes from its star rating, and whether it survives the haul comes from TKPH — the load and speed it can work at without overheating. A deep tread on a long, fast cycle is a tyre being cooked.
Standardised by ETRTO or TRA.