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Abstract
Increment borers are the gold-standard for non-destructive tree-ring coring, but borers frequently get stuck in particularly dense or rotten wood. Here, we present a new screw-assisted auxiliary extractor for the controlled recovery of jammed increment borers. The device combines a push-rotation sleeve, a pull-body housing, elastic wedge blocks, and a locking compression sleeve. These elements form a trunk-reacting mechanism that clamps the exposed borer shaft and converts rotational input into progressive axial withdrawal. A review of existing solutions shows that current devices either focus primarily on facilitating borer insertion, require external anchors, demand repeated manual resetting, or provide only short-travel recovery. By contrast, our newly designed tool offers a compact, field-ready system for safe and staged borer extraction under sustained resistance.