Reducing the kerf width in bandsawing has potential in reducing waste while optimising the yield. To be able to reduce the kerf width, understanding the cutting forces becomes critical. In this work, nine cutting teeth with varying band-body thicknesses and side clearances were tested by cutting both heartwood and sapwood of Norway spruce (Picea abies (L.) Karst.) and Scots pine (Pinus sylvestris L.) in frozen and non-frozen conditions. Single cutting teeth were moved into rotating wood samples in the 90–90° cutting direction, with chip thicknesses of 0.9 mm per cut. The main and normal cutting forces were measured. Scots pine had a higher density than Norway spruce and, therefore, a higher main cutting force. Non-frozen sapwood, non-frozen heartwood and frozen heartwood resulted in similar main cutting forces, but frozen sapwood resulted in significantly higher main cutting forces. Reducing the cutting width by about 45% resulted in an approximately 40% reduction in the main cutting force. The normal forces were not significantly affected by the species or cutting width. Frozen heartwood, non-frozen heartwood and non-frozen sapwood had similar normal cutting forces. Frozen sapwood had negative normal forces, and thus self-feeding was observed. 

Optimizing the cutting tool geometries can reduce waste while increasing timber yield. The indus-try is moving towards thin-kerf rip sawing of timber, and therefore, side cutting and the geometryof the side faces of cutting teeth become more important. Six cutting teeth with varying sideradial- (0, 2, 4, 6 degrees) and tangential clearance angles (2, 4, 6 degrees) were tested by cutting intothe heartwood and sapwood of frozen and non-frozen Norway spruce (Picea abies (L.) Karst.) andScots pine (Pinus sylvestris L.). Single cutting tooth tests were conducted, and the main and nor-mal cutting forces were measured. The main cutting forces were higher for Scots pine due to itshigher density. Frozen sapwood also resulted in higher cutting forces. The normal cutting force offrozen sapwood stood out as it was highly negative (i.e. self-feeding) compared to frozen heartwood,non-frozen heartwood and non-frozen sapwood. An increase in the radial- and tangential clearanceangles, and therefore more room for elastic spring-back, can lead to up to 40% lower main cuttingforces. Higher radial- and tangential clearance angles resulted in less-negative normal forces (i.e. lessself-feeding) for frozen sapwood but remained relatively unchanged for the other wood conditions.

As the sawmill industry is moving towards thinner bandsaws for higher yields, it is important to study the cutting force in more detail. The cutting force can be split into two zones. Zone I concerns the force on the major cutting edge as well as the friction force on the major first flank. Zone II considers the forces on the minor cutting edges as well as the friction forces on the minor first flanks. Zone II cutting can significantly affect the cutting force and has not been studied in great detail. Frozen, non-frozen and dry heartwood of Norway spruce and Scots pine were cut using different tooth geometries and the cutting force was measured. The major cutting edge, clearance, band thickness, minor cutting edge angle and minor cutting edge clearance angle were investigated. The y-intercept of the cutting force–width graph was used as the Zone II force (at this point the Zone I forces are assumed to be zero). The Zone II force contribution to the cutting force was studied. The results show that frozen wood has less elastic spring-back and therefore less Zone II cutting. Dried wood showed a significantly higher degree of Zone II cutting (55−75% contribution to the cutting force). Changing the major cutting edge from 2.87 mm to 1.6 mm resulted in 10–15% higher Zone II force contributions.