UL 498:2019 Figure SC5.1 Grounding Probe

The UL 498:2019 Figure SC5.1 Grounding Probe (SB0704A) is a gauge designed for testing the grounding performance of receptacles in accordance with UL 498:2019. Precision-machined from hardened steel, it features a full spherical tip and a strictly controlled surface roughness of 8 micro-inches. It is a specialized tool used for verifying the mechanical fit and grounding reliability of receptacle grounding terminals during UL safety compliance testing.

Technical Specifications:
• Applicable Standard: UL 498:2019 Figure SC5.1
• Model: SB0704A
• Material: Hardened steel
• Total Weight: 4 oz (113 g)
• Tip Diameter: 0.1840–0.1845 inch (4.67–4.69 mm); full spherical tip
• Cylindrical Section Diameter: 0.5 inch (12.7 mm)
• Effective Length: 0.792–0.797 inch (20.12–20.24 mm)
• Surface Finish: 8 micro-inches (ground in the direction indicated in the diagram)
• Construction: One-piece standard grounding test pin

Test Procedure:
• Ensure the receptacle sample is in good condition, with no deformation or foreign objects obstructing the grounding terminal;
• Align the grounding pin vertically with the receptacle’s grounding slot and apply force equal to its own weight, as required by the standard;
• Check if the grounding pin inserts correctly into the grounding terminal and fits snugly; evaluate the mechanical engagement of the grounding path;
• Observe the terminal’s gripping action and the contact status of the spherical tip to determine if the sample meets UL 498 grounding construction requirements;
• Remove the gauge after testing and clean its surface; avoid impacts that could damage the spherical tip or the ground finish. Applications:
• UL 498 safety certification testing for plugs and receptacles
• Structural inspection of grounding terminals in NEMA-style receptacles
• Third-party UL safety testing in laboratories
• Quality control of grounding performance on receptacle production lines
• Testing for certification bodies, quality inspection laboratories, and electrical component R&D

UL 498:2019 Figure SC5.1