Screw-knob weights are Type II design with sealing cavity for adjusting material. ASTM classes 0-4 have a polished finish. Applications include calibrating Class I and II balances and ASTM class 4, 5 and 6 weights, student laboratory use, and rough weighing operations such as force.

Also known as the International System of Units (SI), Class 0-4 metric weights are available in capacities from 1 mg to 50 kg.