Grinding suggestion

[Haynie]

A while ago I asked about making a specialized tool out of an old file. Some said it was a good idea, others said bad. I decided to go with those who were in support.

Now I have a question about grinding. I keep burning the ends as I grind them. I do not have a slow speed grider. Is there a way to not blue the edges? Would it hurt to keep a cup of oil or water near the grinder to cool off after a few seconds of grinding?

 

[Deadhead]

Not only won't it hurt; you should always have water or oil nearby to quench the metal. It also keeps your fingers from getting burned.

 

[edstreet]

A slow speed grinder would take you some serious time to grind that down as they are designed to put cutting edges on tempered steel.

If you really want to remove metal from any tempered steel like it is hot butter then you need a belt grinder and some cubitron belts. If the metal is already heat treated them follow the golden rule of always always always and always have a big bucket of water handy if it does start to heat up.

Burning of the steel is heat build up from lack of movement, the grit needs to be doing the cutting and not the heat.

 

[Old Codger]

Now I'm totally confused! I used to 'quinch' my wood turning tools in water when they got hot to prevent them from 'blueing' but read that placing a hot tool in water causes the HSS to 'crystalize' which can cause further problems when turning... Soooo, I stopped cooling them off with water and just waited until they cooled down before proceeding... Now this entry...who's correct and what method is best?

 

[duncsuss]

who's correct and what method is best?

Both are correct.

Don't quench HSS.

Quench non-HSS steel (like an old file repurposed by annealing.)

 

[frank123]

Be patient and grind with quick light strokes with cooling time -or water dunking- between strokes.

If you're going to harden it after grinding it really doesn't make any difference since you will be completely hardening and then tempering it to whatever hardness and toughness you want and the "burned" edges will temper out the same as the rest of the metal.

 

[Old Codger]

Duh! I knew that! Sorry, I didn't notice that it was an old file that was being repurposed for a speciality tool...guess, I need to re-read posts before I confuse myself! Thanks for confirming not to water quench HSS! Safe turning to all!

 

[duncsuss]

Duh! I knew that! Sorry, I didn't notice that it was an old file that was being repurposed for a speciality tool...guess, I need to re-read posts before I confuse myself! Thanks for confirming not to water quench HSS! Safe turning to all!

:wink:

 

[Wildman]

I sharpen, carbon, HSS, & exotic steel tools on clean grinding wheels, using light touch.

Goal of sharpening/re-sharpening any tool is just touch up the edge, not remove a lot of metal. Usually takes me a second or two to re-sharpen a tool.

If tool gets too hot to touch, or bluing you just wasting steel!

Takes me little longer changing bevel angle or repairing tool edge will use a coarser wheel, 46 or 60 grit wheels. Reason take longer I pull tool off the wheel checking progress, guess allows steel to cool a bit. Yes, if touch the tool one inch or two down from the tip it is hot, but never blue.

Only suggestion coud offer is clean your wheels, use a lighter presssure, switch to a coarser wheel. Hone after sharpening on grinder.