cold chisels

[Elden]

I have been going through old threads (currently down to about page 31 of the general questions) where I ran across this comment:

Second, if the things you are trying to sharpen are truly cold chisels, and it sounds as if they are, I wouldn't bother trying to sharpen them on the Tormek or anywhere else for that matter. They don't need to be sharpened./i]


The proper angle (general usage) for cold chisels is 60 degrees, increase the angle somewhat for harder metals and decrease somewhat for softer metals.

I have never done a cold chisel on the Tormek and probably never will, but they definitely need a sharp edge. Even the good old dirt shovel benefits from a proper cutting angle, approximately 70 degrees according to one source.

For some things, the bench grinder and files are excellent tools.

Not sure why the last three paragraphs are italics as they were my comments and not showing that way on my post. EH

[Herman Trivilino]

One of my dad's old cold chisels must have had the corner broken off at some point because it looked like he'd sharpened it on his dry grinder at angle that about 45º out of square (I'm not talking about the bevel angle here).  It was also mushroomed on the other end.

It saw the dry grinder followed by the Tormek.

I agree that it's not much use getting a sharp edge and a polished bevel.  It'll disappear on the first blow!

And they say the pyramid builders of ancient Egypt used brass chisels!

[Ken S]

My gut reaction is that a cold chisel should be sharp (and have the mushroomed head ground off for safety).  I wanted to find a source to document this.  From Fundamental Shop Training by Shuman, Monroe and Wright (1945):

"To cut well, chisels must be sharp.  Hence, they should be ground at once when they become dull."  (p 25, discussing cold chisels)  They also suggest a 70 degree angle for cutting cast iron and about 60 degrees for mild steel and wrought iron.

Ken

[Herman Trivilino]

Yes, sharp.  But making them razor sharp with a polished bevel like you would a wood chisel is not necessary.  Just my opinion.

[Rob]

What a great demo gimmick for the Tormek marketing......sharpen a cold chisel so finely it can cut a dovetail :-)

[Ken S]

Doesn't everyone use a cold chisel for dovetails?  They can be a problem with the skinny empire dovetails fashionable across the pond.

Ken

[Herman Trivilino]

I used my cold chisels to dovetail the granite pavers on my patio.  I didn't want them separating so I figured that was the easiest way to get that job done.

[Rob]

I used my cold chisels to dovetail the granite pavers on my patio.  I didn't want them separating so I figured that was the easiest way to get that job done.

Excellent Herman

I laughed out loud at that....I can just see a comedy sketch with a dovetailed patio :-)