The bevel of a plane’s iron, or blade, is the angle on the cutting end of the iron formed when it is initially sharpened (usually by the manufacturer).
Bevel down
Most scrub and bench planes are bevel down – that is, when the blade is secured in the plane, the bevelled edge is on the reverse side of the blade, facing down towards the workpiece.
Bevel up
Conversely, block plane irons are positioned bevel up – that is, the bevel resulting from the sharpening of the iron is on the upper side, facing away from the workpiece.
The blades of bevel-up planes are secured – or “bedded” – at a more acute angle to the sole of the plane than bevel-down planes.
How the bevel affects the cutting angle
With the bevel being on the top side of the iron rather than underneath, it effectively increases the cutting angle so that it’s often not that far short of a “standard” bevel-down iron’s cutting angle.However, the irons of some bevel-up planes are bevelled at more acute angles than usual to give them more of a “slicing” action for end grain work.
No chip breaker
The design of a bevel-up plane is different from the Stanley / Bailey design in ways other than the bedding angle of the iron.For instance, they don’t have chip breakers, the bevel on the iron performs this function, and the depth and lateral adjusters for the iron are different, usually using what are known as Norris-style adjusters. See What is a Norris-style adjuster? for further details. There is no cam on the lever cap – this function is provided by a wheel nut, or knob.
Some woodworkers think the lack of a chip breaker is beneficial, citing the chip breaker as the major cause of clogging: when shavings block up the gap between the leading edge of the mouth and the iron.
Changing the angle of attack
You can alter the “angle of attack” of a bevel-up plane by honing a new bevel on the iron.If the bevel is down, the angle of the cut is always the angle at which the iron is bedded.
Easier mouth adjustment
Adjusting the mouth opening on a bevel-up plane is easier than with most Stanley / Bailey pattern planes. Turning the front knob anti-clockwise enables you to slide the toe section of the sole closer or further away from the blade with ease. The knob is then re-tightened after adjustment.
Most Stanley / Bailey planes require the lever cap, chip breaker and iron to be removed and two securing screws to be loosened with a screwdriver before the frog adjustment screw can be turned, again with a screwdriver, to adjust the opening between the cutting edge and the leading edge of the mouth.A later Stanley design, the Bedrock series, does have mouth adjustment without removal of the blade assembly, but it still requires the release of two screws and adjustment via another screw – again with a screwdriver.
Bevel-down planes
ADVANTAGES
DISADVANTAGES
You can adjust the depth of the iron without taking your hand off the tote, or rear handle
Blade adjustment control is considered better than on bevel up planes
Ideal for planing along the grain and giving a smooth finish to the wood
Overall, slightly more difficult to set up than bevel-up planes
A little top-heavy compared with the bevel-up plane, which can make planing of narrow edges difficult to control laterally
Adjusting the size of the mouth is more difficult compared with bevel-up planes
Bevel-up planes
ADVANTAGES
DISADVANTAGES
Generally easier to set up than bevel-down planes
There is no chip breaker (NOTE: this can be an advantage OR a disadvantage, depending on your experience of chip breakers causing clogging of the plane)
Effective cutting angle of iron is usually slightly lower, so ideal for planing end grain
Low centre of balance means it’s better for planing narrow edges square with the sides of the workpiece
Adjusting the size of the mouth is much easier
You have to take your hand off the tote, or rear handle, to make adjustments to the iron’s depth
There is no chip breaker (many woodworkers believe chip breakers make splitting and tear-out of the wood less likely)
Lower angle of iron considered not so ideal for finishing work, such as smoothing, especially on grains that vary in direction
Wonkee’s best advice is . . .
Get a bevel-up plane if:
You’re going to have just one or two planes
You’re a beginner or you deal with lots of different planing situations that require you to quickly change the angle of attack and/or mouth size
Get a bevel-down plane if:
You have, or plan to get, a number of planes and so can keep each one adjusted to suit a particular situation, avoiding having to repeatedly adjust mouth openings