Follow-up - A Lower Angle Bevel Down Jack Plane

Attempt at converting a bench plane into a low 35* bevel down plane.

- The Start
- Hand Mill
- Flying Frog
- Short Tote
- Final Notes


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This is a follow-up to my earlier Low Angle Bevel Down Jack Plane article where I converted a standard Stanley #5 Jack into a 39 degrees low angle plane. It ended up well, much better than I expected in fact. But I believed I could take it down a few degrees lower. Here's what came up during my attempt at a 35 degrees conversion on another plane. 

What I started with : a recent made in England Stanley #5. 

I chose to go with another #5 Jack for a couple of reasons. First, there are so many of those lying around that I feel a bit less guilt about possibly destroying a perfectly good tool. Also, if this ends as well as the first one, I'd like to add a side handle to it to use as a miter plane, à laRecord T5. Both the 14" length and low 35 degrees cutting angle should make it a fantastic tool for trimming end grain on a shooting board.

Frog stripped and flattened.

First, the frog is stripped from its accessories - it makes it easier to machine the frog face flat (I do this on a belt sander in less than a minute) when both the depth adjuster yoke and the lateral adjuster lever are removed. They're easily put back later by reinserting the pin for the depth adjuster and riveting the lateral lever back on... if we can find room for it. More on that later. Flattening the frog face was necessary on this particular plane, as it had two high spots at opposite corners. Not all frogs need this though.

In the first article, I showed how I ground away a good part of the frog to modify the angle it sits on the plane bed. This time though I want to concentrate on the frog seat cast in the bed instead. It should be easier to get the 35 degrees angle I'm shooting for by simply filing a 10 degrees angle there. The frog would be slanted 10* back from its original 45* : 45* - 10* = 35*. As you can see, this solution feels attractively simple.

The typical post-WWII "Y" shaped frog seat we're going to attack with a mill file.

 Now, from my first experience, I know that going that route will require quite a lot of metal removal. By filing just enough to get that 10* angle, the frog's legs get raised up and do not contact the bed unless more metal is removed to lower the frog assembly. But since cast iron is easily worked, that doesn't bother me much.

Another thing to keep in mind is that the threaded holes where the frog retaining screws go will get shallower and I might have to either shorten the screws or deepen the holes. I made sure I had the right tap just in case. Although it's not an exact match, a 5mm x 0.80 fits the bill. The diameter on the original screws seems slightly bigger than 5mm, but doesn't match anything else, metric or standard in my tap & die set. If someone has more info on the thread/gauge used in those recent Stanley planes, please drop me a line.


I'm gonna check my progress with that simple gauge. The part protruding over the frog seat is the 10* angle. As I file metal away, I'll simply trim the bottom of the gauge to keep my reference angle close to the work.


Hand Mill >>