This is a pneumatic framing cutter (also called a miter cutter or underpinner) — a machine designed to create perfectly aligned 45° corners for professional photo, artwork, and archival frames. Even tiny angular errors compound across four sides, so high-end framing depends on repeatable mechanical precision. The process starts with miter cutting: each frame rail is cut at an exact angle so adjacent pieces form a true 90° corner. Tolerances matter here because a deviation of even fractions of a degree can create visible gaps, stress points, or long-term warping once the frame is under load. After cutting, the joining system uses vertical compression and pneumatic force to insert V-nails or wedges into the underside of the joint. The clamping system distributes force across multiple axes to prevent lateral drift while maintaining flush surface alignment. In professional shops, this reduces cumulative dimensional error and improves structural rigidity without damaging delicate wood ven...