Abstract: [Objective] There is contradiction between the improving quality and increasing efficiency at the same time in wood sawing. The aims of this study were to analyze the influences of the side edges on the surface roughness using circular saw with different parameters of side edges, to solve the contradiction between high feed speed and the better surface roughness, and expected to provide references and guidance for designing the new type of woodworking circular saw.[Method] The concept of the sawteeth with mic-zero degree radial clearance angle was put forward in this paper. The experiments were carried out on the northeast China ash(Fraxinus mandshurica) and high density fiberboard(HDF) as materials and nine kinds of circular saw blades with different sawteeth side edge parameters were used with different feed speed, so as to investigate the influences of different radial clearance angles and straight length of zero degree radial clearance angle on the surface roughness(R_a).[Result] The surface roughness increased with the increase of feed speed, when the radial clearance angle is decreased, the surface roughness saw is decreased.The surface roughness of the sawteeth formed by the sawteeth with radial clearance angles was higher than that of the sawteeth with the sawteeth had a mic-zero-degree radial clearance angle. Especially when the straight length of zero degree radial clearance increased from 0 to 0.5 mm, the decrease trend was the most obvious.[Conclusion] The surface roughness depends on the depth of the saw notch to a certain extent. A small part of side edge which formed the sawing surface participates in actual cutting, and the length of this part of side edge is approximately equal to the feed per tooth. The sawteeth with mic-zero degree radial clearance angle can improve the surface quality of sawing. Besides, under the condition that the other cutting factors remain unchanged, the surface roughness can be improved and the friction also can be reduced between side edges and sawing surface by increasing the feed speed.

Key words: surface roughness, sawing, side edge, the radial clearance angle