That is, shear strength of a doweled joint depends on the compression strength of the pieces holding the dowel, as it is the wood around the hole that fails (lets the dowel pin move). When joining two pieces of wood, we are generally concerned about two different strength values: the tensile strength of the joint (that is, how hard is it to pull the joint apart) and the shear strength of the joint (that is, how hard would it be to get the two pieces to slide past each other). They were joining pretty narrow pieces where a #20 was too wide. Joint Pins. function gtag(){dataLayer.push(arguments);} We have to remember that the main difference between these two jointing methods is the shape of the loose tenon and the round dowel. There is not enough glue on the sides to provide a strong joint. I read so many so-called tests on the strength of the ‘Festool Domino’ or the ‘Round Dowel’ Every time it seems that some comparisons are inaccurate and not comparable. What are the key strength differences between the Festool Domino and a Round dowel? A spiral design is my second choice and a smooth dowel is unacceptable. Third, the dowel greatly enhances the shear strength of the joint. 'dimension4': 'Could you explain what gives dowel pin joints their strength? The Triton Duo Dowel TDJ 600 is a capable machine but not comparable with the Festool. Test results show that dowels are the strongest method for creating this type of joint.