I believe that is correct. The same is true of my little Record plough. 
It pays to score the shoulder(s) of a rabbet or groove with a marking 
gauge or knife for a clean cut.

Don

On 2021-08-31 7:29 a.m., Adam R. Maxwell via groups.io wrote:
>
>> On Aug 29, 2021, at 22:35 , Christian Gagneraud  wrote:
>>
>>> On some of mine, it appears the cutting edge is wider than the body, and
>>> as you shorten the blade thru use, it gets narrower.
>>>
>> Definitely, same here.
> Isn't this intentional? My understanding is that being tapered like this
> keeps the plough iron from binding in the groove. It also keeps the arris
> of the iron from wasting away the sides of the groove, which is a problem
> I've had with Stanley versions: it's really easy to end up with a ragged
> groove if you don't keep the handle perfectly vertical.
>
> Adam
> (who hasn't used a plough since last year, so could be all wrong)
>
>
>
> 
>
>

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