January 19, 201016 yr -------------------------------------------------------------------------------- I'm interested to know how fine a finish would be best on blades prior to heat treating, i.e. hardening/quenching and tempering. My approach to date has been to polish the blade to 220/320 grit. My rational is that 1) it is easier to work the softer steel and 2) removing any deeper scratches/grind marks reduces the possibily of cracks or fractures along them. I haven't seen any negative consequences from this finish but wonder if there could be.
January 19, 201016 yr I asked a similar question once. the reply i got was.... "Good practice to anneal first after you forge..it is easier to sand or grind everyting to shape and smooth then. Then it needs normalized. Then it needs to be hardened ,,then tempered. What you do with your piece is very dependant upon what kind of steel it is. Some steels can be hardened with oil some air some water. To use the wrong quenchant will ask for a failure up front. If your steel has too little carbon in it you can go ahead now and finish your letter opener as it will not harden to make a useable blade. This is minimal thoughts..everything you need to know is on this site. just search a bit. That is except for your blade steel,,only you know wot you used. Have fun" So i have gotten into the idea that the blade should be as close to finished without completely finishing the edge before you even normalize it.
January 20, 201016 yr i use 1080 so, i forge, i heat back up and put in lime...then after forging i normalize 3 x and then hatden and asap...10 min oe less put in the oven at 300 and let cool and then at about 340 hope this helps, jimmy
January 20, 201016 yr Well 220 grit should be fine for finishing your blades, just make sure that the scratches run parallel along the blade edge and spine prior to quenching, that should help prevent any stress cracks from forming along the edge and spine, just a tip, hope this helps.
January 20, 201016 yr yup thats pretty much how i do it as well, forge, anneal, grind/sand, norm x 2 or 3, check it out real good, harden , test hardness(with a sharp. file) then temper(dif. temper prosedures depending on the blade shape and use)then i test the finished product .but yeah i like to get it mostly done befor the heat treat, its easy...er to work and you have less chance of messing up your heat treat. but most of my work is done with the hammer for minimal sanding and grinding, this however take practice.
January 28, 201016 yr I generally forge, let blade cool down in the forge after I shut it down (gas forge). Anneal next day and let cool in vermiculite. Grind/sand to 600 grit, leaving the edge roughly as thick as a dime. Harden and clean oil from blade surface. Differential heat treat with either a torch or a heavy block of heated steel, depending on blade size. Finish sanding the blade. Assemble. Sharpen. The sharpening is slow because of the hard cutting edge I leave, but well worth it once I get there.
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