Scythe peening tool - GIF

[neilbourjaily]

The channel. Is the channel in order to channel dust and bits from the cutting edge out the tip?

[Inner]

The channel at about the 30 sec mark is a result of the tool profiles on the blade. It is not functional. Use of the tool is optional for peening, it is commonly done freehand with a hammer and small anvil. If lacking experience as to where to hammer, the tool helps you move just the right amount of metal to get a razor thin edge. Two tools are often used (notice he has 2 in his hand at the start), a bigger one to rough in the shape and then a smaller one to refine the edge. This also results in a 'channel' of 2 parallel lines.