What is TSR?
TSR (Technically Specified Rubber) is block natural rubber graded by measured technical parameters instead of visual inspection.
TSR is an umbrella term for block rubbers graded against a technical specification — including SMR (Malaysia), SIR (Indonesia), STR (Thailand) and SVR (Vietnam). Each origin runs its own scheme, but the tested parameters are broadly comparable.
This contrasts with visually graded rubber such as RSS (Ribbed Smoked Sheet), where quality is judged by appearance. Technical grading gives buyers a consistent, contract-ready specification, which is why TSR 20 grades dominate tire supply chains and exchange trading (e.g. SICOM).