Veritas 50º Replacement Blade for Low Angle Smoothing Plane, A2 Steel
The Veritas 50º Blade for their Low Angle Bevel Up Smoothing Plane is made from A2 Tool Steel.
When adding the bevel angle of this blade to the original bed angle of the plane at 12º, you have a effective 62º cutting angle, 12º more than ("York Pitch @50º combined angle) which excels at smooth planing the most difficult or highly close and cross grained wood. A good example of this kind of timber is Birdseye Maple, where tear-out can be extremely difficult to control.
The resulting cutting angle of 62° produces what is known as a Type II chip (or shaving), one created by wood failure right at the cutting edge, eliminating tear-out on even the most difficult grains. Planing wood at this cutting angle is quite a workout – but the results are definitely well worth it. This is a wonderful blade to add to your arsenal of Low Angle Bevel Up Soothing Plane accessories.
As this is a smoothing plane blade, it is recommended that you slightly camber the extreme edges of the blade to eliminate blade lines in the finished surface.Veritas Lapped Plane Blades
Lapping the blade is the critical first step when preparing a blade for use. The reason for this may not be obvious until you understand that the sharpness of a cutting edge is determined by the intersection of two surfaces (the bevel and the opposing face), and that the smoother and flatter these two surfaces are, the keener the intersection. The lapping process can be an arduous task, especially when dealing with today's hard tool steels. This process, when done by hand, involves numerous steps and will require a good deal of your time to achieve an acceptable working surface.
To reduce the time and effort you spend on this activity, Veritas now laps their A2 and O1 plane blades on the face (non-bevel side) to a flatness tolerance of ±0.0002" or better over the working surface, and with an average roughness surface finish of 5 microinches (0.000005") or better. Because you begin with a blade that has already been lapped flat, your efforts may now be focused on providing the final polish to the face and honing the micro-bevel – tasks that require significantly less time and effort than lapping the blade face.
On Veritas regular and bevel-up plane blades, the working surface is the section of the face that extends from about 1/8" below the bottom of the screw slot to the cutting edge; on shoulder and bullnose plane blades, it is the widest section of the face from the shoulder to the cutting edge. Average roughness (Ra) measures the height variations in the surface over a given area and then provides an average roughness
value to represent the surface finish – the lower the value, the better the finish.