Can you guys explain the 25 Deg & 30 Deg sharpening angles.

[Whitespider]

I file most of my chains at 30[sup]o[/sup] with a slight upward tilt to the file.
But I keep a couple semi-chisel chains filed level at closer to 25[sup]o[/sup] for cutting old dirty blow-downs and such.
Likewise, I keep one full-chisel closer to 35[sup]o[/sup] for cutting clean softwood, like as pine, fir, cedar, etc.

A full-chisel at 35[sup]o[/sup] will make short work of a softwood tree.

 

[Chris-PA]

:agree2: Very true, the best way is to free-hand (no guide), and look closely at what you are doing.

Filing without looking closely is a gamble at best!

I agree. Sometimes I think all these guides and such are an attempt to avoid watching what you are doing.

And when I file in poor light and look at it later I'm often disappointed. Life used to be easier when I could still see!

 

[Joe Kidd]

Square is just the smoothest fastest cutting chain to have. A nice filed 30 degree round chisel is no slouch either.

Someone please explain the square cut and the best way to acheive it. Photo examples? Thanks.

 

[Tzed250]

Someone please explain the square cut and the best way to acheive it. Photo examples? Thanks.

Look at the picture in my signature. It is achieved with a double bevel file or a dedicated square grinder.

 

[paccity]

 

[mdavlee]

Here's some pictures of ground and square filed chains.

 

[Joe Kidd]

Correction

For what it's worth I file all of my chain at 30° with 0° tilt using Stihls bench file guide.

Just checked my jig today and it's set to 5° tilt. I run full chisel on everything.

 

[Chris-PA]

I really need to try me some square. LOL - a fat Mac Silver Eagle 3420 with a 24" bar and square ground. It's definitely gonna happen.