Thread: what temperature is safe for a blade?

Hi,

so when you clean/sand a blade, the temperature can potentially get pretty high.
At what temperature does the metal actually start to change its properties
?


Redwoood

It depends on the steel but if you are cleaning and sanding by hand even buffing on a wheel I wouldn`t worry about it but if your gringing I would make one pass and in the water and have it on very low speed
Kind regards Peter

Just one addition to the buffing. If you are using a dremel and go at too high a speed then you can ruin the edge by overheating it. This is quite easy to do even if you are only buffing it.

I polish the blade faces by hand to avoid ruining the edge.

A good rule of thumb is if it is too hot to hold then you chance ruining it but this is overly concervative. I prefer to err on the side of caution.

Originally Posted by vladsch

A good rule of thumb is if it is too hot to hold then you chance ruining it but this is overly concervative. I prefer to err on the side of caution.

But that would mean that even 100 centigrade would be dangerous. A lot of people use boiling water to sanitize their blades. Or is this part of the 'overly conservative' ?


Redwoood

The rule of thumb to use is "uncomfortably hot" .
When it gets that hot then dip the razor in cool water until it cools down. Please note that it takes very little time to get that hot with either a buffer or a Dremel. Do not keep the wheel in one spot, keep it moving along the blade.

Hope this helps,

Now I'm getting really curious. so what about boiling water? is that too hot? I wouldn't think so but you guys are frightening me.

With regards to cooling the blade, is it safe to cool a hot blade in cold water? couldn't the sudden temperature drop warp the blade?

Redwoood

Boiling water is fine.

The reason to keep the blade cooler when working is because the edge is very thin. If you work near the edge and the blade is too hot to hold then the edge can be much hotter and will loose its hardness.

Boiling water will not overheat any part of the blade higher than 100C so there is no danger.

Typically, a temperature of 300 degrees fahrenheit is necessary to soften hardened steel at all.