ASTM Class 5/7 Metric Cast Iron Calibration Weights - Slotted Interlocking Weights

by Rice Lake



Our cast iron weights undergo a special phosphatizing process in which the metal is thoroughly cleaned and mildly etched to allow exceptional finish adhesion. The weights are then coated with a layer of chip-resistant paint which conforms to NIST Handbook 105-1 standards. This two-step process ensures a long-lasting finish that greatly reduces the possibility of corrosion. 


  • Slotted weights and hangers for suspended weighing 
  • Nominal value marked on weight
  • Weight capacities of 10 kg/20 lb and up meet NIST Handbook 105-1 and Handbook 44 specifications
  • Metric weights designated by gold paint
  • Avoirdupois weights (pound) designated by silver paint
  • Serial numbers may be stamped on weights (optional)

Classes Available:

  • NIST Class F
  • ASTM Class 6 and 7


  • Field standards for testing industrial devices Class III, Class IIlL or IIII
  • Testing for non-marked scales without Class designation
  • Verifying scales are within specified accuracy and tolerances

Additional Accessories upon Request

  • NIST Traceable Certification
  • Serial Number