Full chisel sharpening.

[Timber Man]

How will you turn it into the top one ? The top one has a square cornered cutter , the bottom one (semi) has a round one .

[MattyF]

The gullet is round on the chisel and square ground on the semi chisel

[Sawchip]

How will you turn it into the top one ? The top one has a square cornered cutter , the bottom one (semi) has a round one .

 

If you use a round profile file on the bottom one you will end up with the top ones profile...use a square file method or a grinder (a flat disc will give a square grind and a rounded gullet bottom ) and you more or less keep what it is now.

[Mick Dempsey]

How will you turn it into the top one ? The top one has a square cornered cutter , the bottom one (semi) has a round one .

 

Are you sure you've got them the right way round?

[Stubby]

Square ground chisel can be filed with a round file and then it will become round ground chisel . Both are full chisel neither are semi chisel . Both the full chisel will have a point for the working edge . I disagree with the thing about semi chisel staying sharp longer than full chisel . If a chain is dull , its dull . Just me . Oh if you do decide to sharpen square ground chisel with the square edged files the correct way is the opposite to a round file . You file from the point inward were as with a round file you file from the inner edge outward .

[Mark_Skyland]

They both look like full chisel to me. The bottom being square ground. I have never tried square ground chain so I can't comment on how easy or difficult it is to sharpen.

[Stubby]

They both look like full chisel to me. The bottom being square ground. I have never tried square ground chain so I can't comment on how easy or difficult it is to sharpen.

 

Its up there with fruit tree pruning ...a black art !

[Mick Dempsey]

Ah, now we're getting to the bones of it.

 

The bottom one is square ground, i suspected that to be the case.

 

Closer up pic...

[agg221]

Square filed vs. round filed;

full chisel vs. semi-chisel

 

are two separate, independent things. In theory, the angle is more consistent with square grinding as the ground face is flat, rather than part of a circle. This means it is not affected by the minor variation in depth of file position which round filed chain is, so being a bit more even should cut a bit faster, however the trade-off is that it needs a different sort of file and file use is less efficient as you don't just move it round a bit when it wears.

 

Semi-chisel has a rounded corner whereas full chisel has a complete, right-angled corner between the side of the tooth and the top plate. Full chisel cuts faster as the whole cutting edge is presenting uniformly, but the exposed outer corner is vulnerable to chipping off with a bit of grit. Once it has, you then have to take the whole top edge back to the depth of the chip, so typically you end up filing more frequently and removing more metal with full chisel, unless your wood is very clean.

 

The photos are from the wrong side to see, but judging by the light reflections on the partly visible right-hand tooth on the lower chain it looks like square ground semi-chisel. The top one looks like round filed full chisel.

 

Alec

[Sawchip]

They both look like full chisel to me. The bottom being square ground. I have never tried square ground chain so I can't comment on how easy or difficult it is to sharpen.

Take a look at the bottom right of the main pic..you can see the back view of the semi chisel chain...hard to tell from the centre views of the chain isn't it . If you sharpen your chains with a grinder rather than a file then the bottom chain is just closer to the profile you end up getting from most normal chains you buy. Sq ground off the peg chain is not something i have seen offered .

Edited March 5, 2017 by Sawchip