Chain sharpening...

[Ty Korrigan]

By grinding.

Here in La Belle France I am told by now 3 other arbs that this can 'case harden' a chain and so make it difficult to sharpen by hand.

My question is this...

"Really?"

Answers please!

Ty

[Pat Ferrett]

Done incorrectly yes

Done correctly no

[Joy Yeomans]

as i understand it, and i do use a chainsaw, i have always hand sharpended, the lads dont use grinders as we have to sharpen our chains in the forest by hand when dull, and if using a mechanical sharpener/grinder it heats the blade unless you buy a really expensive one or are very accurate using it, once the tip is hot or blued you cant then get that tip sharp using a hand file again, its tempered it

 

joy

[tuttle]

as above, correct.

 

look up: Tempering - Wikipedia, the free encyclopedia

[Stubby]

By grinding.

Here in La Belle France I am told by now 3 other arbs that this can 'case harden' a chain and so make it difficult to sharpen by hand.

My question is this...

"Really?"

Answers please!

Ty

 

I would have thought it the opposite . If you get it too hot you will temper it and soften it .????

[treequip]

as above, correct.

 

look up: Tempering - Wikipedia, the free encyclopedia

 

It's not tempering, it's hardening. Tempering is what you do to steel after its been hardend.

 

Incorrect use of a chain grinder will result in excessive localised heating, this will cause the steel to harden and you won't be able to sharpen it with a file. Re grinding will be the only way to go.

 

When done properly grinding is perfectly acceptable.

[Ty Korrigan]

Thank you the responses so far.

So, I guess the technique is to touch light and fast several times rather than holding the wheel to the chain continiously.

Basically, at the end of the day, I have several chains to sharpen and what I really want to do is go home...

So I am considering buying a grinder from Honey Bros (£450+v.a.t+

If I win time then over just a few years it will have paid for itself and also helps my tendonitus.

Cheers

Ty

[Chris Sheppard]

Thank you the responses so far.

So, I guess the technique is to touch light and fast several times rather than holding the wheel to the chain continiously.

 

That seems to work in my limited experience of grinders. Grinder gets brought out for badly damaged chains and we've always been able to resharen by hand afterwards, if anything it's just the profile of the cuttr that's slightly different (much the same way as on a new chain the firs time it's sharpened)

[difflock]

From my "O" Level metal work classes (was there such a thing?) I remember "hardening & tempering" as being the process where the correct grade of carbon steel was first highly polished, then heated red-hot before being "quenched" in water or oil (or menstural blood for Zulu spears apparently), to rapidly cool, this steel would then have been so hard as to be brittle, therefore then repolished before being heated to blue heat or straw coloured heat (showing in a rainbow effect across the polished steel) dependant on the level of hardness to be retained in the steel, before being allowed to air cool, ie slowly.

I cannot therefore see how grinding "hardens" as the chain is not "quenched"

Rather one is overheating the steel and loosing the hardening effect by overtempering. It should then actually be softer and easier to file BUT will not retain the edge in use.

I liked Metal Work.

Simples

think of the point of a chisel for an example.

[treequip]

From my "O" Level metal work classes (was there such a thing?) I remember "hardening & tempering" as being the process where the correct grade of carbon steel was first highly polished, then heated red-hot before being "quenched" in water or oil (or menstural blood for Zulu spears apparently), to rapidly cool, this steel would then have been so hard as to be brittle, therefore then repolished before being heated to blue heat or straw coloured heat (showing in a rainbow effect across the polished steel) dependant on the level of hardness to be retained in the steel, before being allowed to air cool, ie slowly.

I cannot therefore see how grinding "hardens" as the chain is not "quenched"

Rather one is overheating the steel and loosing the hardening effect by overtempering. It should then actually be softer and easier to file BUT will not retain the edge in use.

I liked Metal Work.

Simples

think of the point of a chisel for an example.

 

 

I can see how you would come to that conclusion but here are a few facts to allow you to re considder

 

Hardening occurs when you heat the material, the rate of cooling will have an effect but even if you let the material air cool it will still be hard and brittle, its the heat that hardens not the cooling.

 

There is no such condition as over tempering, the material is either tempered or not but grinding cant temper the material because it wasn't hard in the first place.

 

Retaining the edge in use has little to do with the condition of the cutter, rather the cutting edge is the few microns of chrome on the surface of the tooth. The tooth itself is made of a softer steel that can be easily filed out from under the chrome, you can't file chrome so they make the cutter body suitable to be filed out from under the chrome leaving a good cutting edge.