Eur. J. Wood Prod. (2011) 69:677–679 DOI 10.1007/s00107-010-0501-3 BRIEF ORIGINALS KURZORIGINALIA Bending and fatigue strength of mortise and tenon furniture joints made from oil palm lumber Jegatheswaran Ratnasingam · Florin Ioras Received: 7 July 2010 / Published online: 23 November 2010 © Springer-Verlag 2010 Abstract The bending and fatigue strengths of rectangu- lar mortise and tenon furniture joints made from oil palm lumber and solid Rubberwood were compared. The results showed that the ultimate bending moment of the oil palm lumber joints were half of the strength value of Rubberwood joints. The results showed that for both materials the allow- able design stresses for rectangular mortise and tenon joints could be set at 20% of its bending strength. Biege- und Dauerfestigkeit von Zapfenverbindungen in Möbeln aus Ölpalmenholz 1 Introduction Furniture are often produced using rectangular mortise and tenon joints, especially for joining the back leg and the side rail of chair frame construction (Eckelman 1999). Tighter fitness between the mortise and tenon, the use of materials of higher density and lower moisture content and larger joint dimensions have a strong positive influence on the overall strength of the joints (Erdil et al. 2005). Although round mortise and tenon joints are efficient load bearers and are highly resistant to cyclic loading, Tankut and Tankut (2005) found that rectangular mortise and tenon joints to be 15% stronger due to the greater surface area for load distribution. J. Ratnasingam ( ) Faculty of Forestry, Universiti Putra Malaysia, 43400 UPM, Serdang, Selangor, Malaysia e-mail: jegaratnasingam@yahoo.com F. Ioras Faculty of Technology, Buckinghamshire New University, Queen Alexandra Road, High Wycombe, Buckinghamshire HP 11 2 JZ, UK Strong joints are essential in furniture as furniture failure often occurs at joints, which are subjected to both static and cyclic loads (Ratnasingam et al. 1997). Consequently, fun- damental data on the strength performance of joints are im- portant if a particular material is to be promoted as a furni- ture material. Recently, oil palm (Eleais guineensis) lumber has emer- ged as a potential raw material for the manufacture of edu- cational school furniture in the South East Asian region, on the basis of its acceptable strength and working properties (Ratnasingam and Ioras 2009). Nevertheless, the strength performance of joints made from oil palm lumber remains unknown, and the lack of information restricts its use in furniture frame construction. Therefore, a study was under- taken to evaluate the ultimate bending moment and fatigue strengths of rectangular mortise and tenon furniture joints made from oil palm lumber in comparison to the joints made from solid Rubberwood (Hevea brasiliensis), which is an es- tablished furniture material. 2 Methodology In this study, the T-joints were assembled using oil palm lumber and solid Rubberwood, glued together with a 40% solid content PVAc adhesive. The joint components con- sisted of a 450 mm × 30 mm × 25 mm leg member and a 350 mm × 55 mm × 25 mm rail member. A total of 50 repli- cates were produced for each of the experimental material. The moisture contents of the assembly were maintained at 10 ± 2% moisture content. The rectangular mortise were cut using a mortising machine, and had a dimension of 40 mm in length, 20 mm in width and 12 mm in thickness. The tenons were cut using a single-end tenon machine to the dimension of 39.75 mm in length, 19.85 mm in width and 11.85 mm