An orientation adjustment device for a circular saw having a base plate and a saw blade assembly movably mounted on the base plate, comprising: an adjustment assembly operable to adjust an orientation of the saw blade assembly relative to the base plate, the assembly including an axle movably supported on the base plate to adjust the orientation of the saw blade assembly; and a release mechanism, characterized in that the release mechanism includes: at least one torsion spring (42, 43) wound around said axle, said torsion spring (42, 43) including a coil portion (42c, 43c) having a free inner diameter smaller than the outer diameter of said axle, and an anchor leg (42a, 43a) and a release leg (42b, 43b) projecting outward from said coil portion (42c, 43c), said anchor leg held in a substantially fixed position relative to said axle and said release leg (42b, 43b) arranged to move relative to said axle in a direction to uncoil said coil portion (42c, 43c); and a manually operable release element supported relative to said axle so that movement of said release element moves said release leg (42b, 43b) from a first state in which said coil portion (42c, 43c) is engaged about said axle and a second state in which said coil portion (42c, 43c) is unwound to a diameter greater than the diameter of said axle. an adjustment assembly operable to adjust an orientation of the saw blade assembly relative to the base plate, the assembly including an axle movably supported on the base plate to adjust the orientation of the saw blade assembly; and a release mechanism, characterized in that the release mechanism includes: at least one torsion spring (42, 43) wound around said axle, said torsion spring (42, 43) including a coil portion (42c, 43c) having a free inner diameter smaller than the outer diameter of said axle, and an anchor leg (42a, 43a) and a release leg (42b, 43b) projecting outward from said coil portion (42c, 43c), said anchor leg held in a substantially fixed position relative to said axle and said release leg (42b, 43b) arranged to move relative to said axle in a direction to uncoil said coil portion (42c, 43c); and a manually operable release element supported relative to said axle so that movement of said release element moves said release leg (42b, 43b) from a first state in which said coil portion (42c, 43c) is engaged about said axle and a second state in which said coil portion (42c, 43c) is unwound to a diameter greater than the diameter of said axle. at least one torsion spring (42, 43) wound around said axle, said torsion spring (42, 43) including a coil portion (42c, 43c) having a free inner diameter smaller than the outer diameter of said axle, and an anchor leg (42a, 43a) and a release leg (42b, 43b) projecting outward from said coil portion (42c, 43c), said anchor leg held in a substantially fixed position relative to said axle and said release leg (42b, 43b) arranged to move relative to said axle in a direction to uncoil said coil portion (42c, 43c); and a manually operable release element supported relative to said axle so that movement of said release element moves said release leg (42b, 43b) from a first state in which said coil portion (42c, 43c) is engaged about said axle and a second state in which said coil portion (42c, 43c) is unwound to a diameter greater than the diameter of said axle.