Fig. 5: Series 2 interlocking profile depth-selection tests—load and displacement.
From: Engineered wood products for circular construction: a multi-factor evaluation of lamination methods

The number following the shape code indicates the profile depth (i.e., 2-01-SQ1 refers to: series 2, test 1, square shape interlocking surface, 1/32in depth). a Square surface profiles, b triangular surface profiles, and c truncated triangle surface profiles.