Proof Load Test Weight Set – 1T

Proof load test weights are precision-manufactured cast iron or steel weights used to apply a controlled, predetermined overload to lifting equipment during statutory and routine compliance testing. Their primary purpose is to verify that cranes, hoists, lifting beams, and associated rigging hardware can safely sustain loads in excess of their rated capacity without permanent deformation, structural failure, or loss of function. By subjecting equipment to a proof load — typically 125% of the Safe Working Load (SWL) as specified by applicable regulations — operators and inspection bodies can confirm structural integrity and identify any latent defects before the equipment enters service or is returned to operation.

During certification testing, proof load weights are applied to the lifting equipment under controlled conditions by an accredited inspection body or competent person. The equipment is loaded to the required proof load, held for a specified duration, and then thoroughly examined for any signs of distortion, cracking, or mechanical failure. Upon successful completion of the test, the equipment is certified to its SWL and issued with the appropriate documentation — such as a test certificate or thorough examination report — confirming it is safe for use. This process is a mandatory requirement under legislation including the Lifting Operations and Lifting Equipment Regulations (LOLER) and equivalent international frameworks, ensuring that all lifting equipment in service meets minimum safety standards.

To ensure the accuracy and reliability of proof load testing, the weights used must themselves be traceable to recognised national and international standards. Our proof load test weights are manufactured and verified in accordance with OIML R 111 (Class M1) recommendations, providing confidence in their nominal value and metrological accuracy. Calibration and verification services are carried out by UKAS-accredited laboratories, ensuring full traceability to national measurement standards. This traceability is essential for compliance audits, third-party inspections, and legal-for-trade applications, giving engineers, safety managers, and inspection bodies complete confidence in the test results produced.