Thread: retemper.....

some of you guys will remember that i built this...



out of a cheap chinese made file a couple weeks ago...

well i have been having fits with honing and edge holding..... i can get it to hair splitting perfection then upon starting to shave it makes 2 good strokes and starts tugging... needing restropping to continue shaving with... *(major PITA)...

when i was shaping this i believe i chased the temper out near the edge while being a tad impatient while buffering... fortunately it is a wedge and i should be able to retemper the edge without turning into a S..... *(hopefully)....

i have read a bit on tool steel and found that 400degrees for 2 hours then allow to air cool should bring it to 62-64 rockwell....

any suggestions? warnings? anecdotal quips? please speak up... the oven is pre-heating....

Um, the idea of a cheap chinese file makes me nervous. There are modern manufactured files that are merely case hardened mild steel. That means you can probably sharpen it and it will perform just as you describe.

400 degrees for some steels like 1095 may be too hot but the steel would have to be a known variety to make a better judgement. Most old files (Nicholson and Black Diamond for example) were 1095 or W1.

If you reheat and quench, if this blade is hard, it should "skate" another file. There won't be any abrasion of the razor by another file. If the file cuts into the razor, it's not harder than the file.

If it becomes a lost cause you can still learn a great deal by heating the blade to non magnetic and quenching in water. If it cracks, those files would be potentially good stuff for making razors (assuming you can get more of them). If it does not crack, clamp it in a vise and try to break it. If it's hard it will snap clean. If it's not hard it will only bend. That sacrifice is a good (painful sometimes) routine to have when questions like this come up. But at least you'll know more.

hope this little bit helps.

i misspoke when i said "retemper"... it was better said "reharden"........

i heated in the oven for 2 hours @400f.... then allowed to aircool slowly...... this turned the metal between a light and med straw color... indicating a actual temp of ~425ish.... anyway after cooldown i re-bevelled it on the 1000 and went to 6000.. then a light CRoX on balsa and stropped the living poop out of it....

it made a complete shave without restropping.....

this is of course a experiment... i have plenty of other shave ready razors so this will be my test bed........

i will crank up the propane tomorrow and take it to austenite status........ then if it survives the quench i will drop it in the oven @ 350degrees for 2 hours then air cool it ........... that should give me a ~65rockwell.....

*(if i am wrong please please someone correct me...)....

to my knowledge this is made of O1 steel.......i could be wrong.... but the color was spot on with the scale for O1 steel.......

[QUOTE=paco664;819589]i misspoke when i said "retemper"... it was better said "reharden"........

I think your terminology was correct, you heat (to a cherry red) and quench, to harden. You then re heat, to an appropriate temperature and allow to cool slowly to temper.

Old textbooks often substitute temper for harden. I knew what you meant Paco.

Straw color usually is a good sign, but non hard mild steel will also take a straw color. If it's performing, there's no real issues to discuss other than being fussy about a bunch of unknowns. "A great shaver" is mighty close to the mark of usefulness and quibbling about what kind of steel it is merely curiosity.

I'm pretty sure that O1 would be an odd steel for a file. Not impossible, but most files are desired to have a hardness at or greater than the potential hardness for the steels they will be used to file upon. O1 can't be pushed far enough regularly to produce high hardness like the fast quenching steels.

To get O1 Rc 65 you should only temper them at 200 F, not greater, and that's if you quench it fast enough initially. It will be brittle and much harder to hone too. At 400 F I would expect an Rc hardness of 59, at 350 Rc 60, maybe 60.5. So says the Heat Treater's Guide and that's what I get out of O1 in my shop.

hmm... that makes sense.........

so i am not dealing with O1...... based upon your logic here....... then i have no clue as to what it is really made of.....

bright side is that it is holding an edge now so whatever i did was a *(semi) success....

seeing as i don't really care about this particular razor, i can/will mess with it to the point of destruction.......

so tomorrow we go old school......... heat to the point of no magnetization with an immediate *(vertical) quench in either peanut or corn oil......

then a ~2hour bake at 250 with a nice soothing air cool followed by a vigorous honing just to see what will happen.......

i feel like dr. frankenstein........

will it live?? will i make too much of a mess and make the wife angry?? tune in tomorrow...

and thank you very much for the info...

You have been bit by the steel bug but good. Start making plans for the next Minnesota Razor Meet at Mike Blues this winter!

Don't go for 65. It will be impossible to hone, and (I assume) very brittle.
I have honed known 61-62 HRC blades and it was a monster to hone. Hours and hours to get a bevel set properly.
Keeping in mind that the scale is exponential, 65 will be a nightmare.
Imo, 59-61 is the ideal range for a good razor.

Originally Posted by randydance062449

You have been bit by the steel bug but good. Start making plans for the next Minnesota Razor Meet at Mike Blues this winter!

The meet in Ohio in September will be closer and sooner for someone in Miami. But we should start planning something for the frozen toe segment.

...heat to the point of no magnetization with an immediate *(vertical) quench in either peanut or corn oil......

then a ~2hour bake at 250 with a nice soothing air cool followed by a vigorous honing just to see what will happen.......

i feel like dr. frankenstein........will it live?? will i make too much of a mess and make the wife angry?? tune in tomorrow...

That sounds like a good plan, except the making the wife angry part. See how the blade behaves when you hone it after the low 250 tempering cycle. If it hones the stone, then back in the oven at 350 for a couple hours and test the hones again. You'll find a sweet spot.

Before I got my own heat treatment furnace and used old motor oil as a quench, I learned to be really careful tempering things in the kitchen oven. Finding the temper of a latina because her kitchen stinks, is not something I recommend, nor repeat.