Monitor Arm Clamp Spreader Plate
A 130 x 84 mm ribbed load-spreading plate that goes between a monitor arm's C-clamp pressure pad and the underside of a hollow-core or thin veneer desk (IKEA-style particleboard, 18-25 mm tops) so the clamp stops denting or cracking it. A 56 mm square, 5.6 mm deep pocket captures round or square clamp pads up to 56 mm so the plate cannot slide out, the flat 3.4 mm contact face spreads the bolt load over roughly 7x the pad area, the front long edge is left wall-free so the plate tucks right up against the clamp spine at the desk edge, and four counterbored 4.5 mm holes take M4 screws for a permanent install on a solid-wood desk.
desk monitor-arm desk-clamp reinforcement