All UKAS 5kg Slotted Weights are calibrated here at JWS to the specification listed below:

M1 +/-250mg.


UKAS Test Weights are sent to Trading Standard to be tested and Certificated.

They must have a Serial Number stamped on to the weight. 

Only one UKAS Certificate is needed per batch of weights on the same order. Please remember to add this to your basket available back on the Test Weights page.