KP1981-4 - Lincoln Electric Shade 11 Super Visibility Filter Plate 4.5x5.25

Technical Overview of the Lincoln Electric KP1981-4

The Lincoln Electric KP1981-4 is a passive filter plate designed for industrial welding applications requiring a fixed Shade 11 protection level. Part of the "Super Visibility" series, this lens is engineered to provide high optical quality, minimizing the distortion often associated with lower-grade filter plates. The unit measures 4.5 inches by 5.25 inches (114mm x 133mm), adhering to the standard "large view" industry dimensions for passive welding helmets. This specific sizing allows for a broader field of view compared to the smaller 2x4.25 inch alternatives, facilitating better spatial awareness for the operator during complex fabrication tasks.

Constructed from high-grade optical glass, the KP1981-4 offers distinct advantages in thermal stability and scratch resistance. Unlike plastic lenses which may warp under extreme heat or scratch easily during cleaning, this glass filter maintains its structural integrity and optical properties over a longer service life. The Shade 11 darkness rating is calibrated to filter out harmful ultraviolet (UV) and infrared (IR) radiation generated during electric arc welding, specifically suitable for amperage ranges typically found in heavy Stick and MIG welding operations. Compliance with ANSI Z87.1 standards ensures that the plate meets rigorous impact and optical clarity requirements necessary for occupational safety.

Installation of the KP1981-4 is straightforward, fitting into any standard welding helmet retaining system designed for 4.5x5.25 inch plates. It is intended to be used in conjunction with a clear cover lens (polycarbonate or glass) on both the front and rear to protect the filter plate from spatter and impact damage. Regular inspection of the filter plate is recommended to ensure no cracks or pitting compromise the protective qualities of the shade.