CBrann Posted February 22, 2009 Share Posted February 22, 2009 I made a knife from carbon steel cable, when I hardened and temered it, the blade took on a curl, (twisted and warped and turned in a spiral) Any ideas on preventing this in future. I did re heat, bend in an opposite approximate direction from what it did before, but upon re-quenching it took on its previous spiral twist and curl. Quote Link to comment Share on other sites More sharing options...
CurlyGeorge Posted February 22, 2009 Share Posted February 22, 2009 CBrann, don't know what happened. I have only made about three, but haven't had any curl or corkscrew. This was the first one that I finally completed. Then forgot to take a completed picture. How thin are you pounding them out? I left the spine of mine at least 1/8 inch. I put the bevel from the middle to the cutting edge, instead of tapering all the way from the back of the blade. That might have made it a little bit stiffer, but it didn't get funky in the water quench. Quote Link to comment Share on other sites More sharing options...
JPH Posted February 22, 2009 Share Posted February 22, 2009 Hello: Having made a couple of these..I have to ask..what kind of cable? I mean the grade of steel, the number of strands, the type of twist etc? Also, please explain your hardening and tempering process. I may be able to tell you what happened... JPH Quote Link to comment Share on other sites More sharing options...
CBrann Posted February 23, 2009 Author Share Posted February 23, 2009 The cable in question is I think... 1" dia 20 something X6 IWRC Right lang lay, IPS or EIPS NON GALVANIZED , it is new, I bought it from a place that services fishing boats. I forge welded the first 4 inches and drew it out to the blade then forge welded the last inch or so for the butt. The blade is about 1/8 inch or thicker (haven't put the mic to it). I ground it, heated it to black.. or a little more.. non magnetic, quenched in water, then shined it up, put it in the oven at 350 for 1/2 hour, and let cool slowly. I noticed the twist after quenching, but thought it might decline after tempering, and have tried straightening untempered blades before.. they usually break. Tried to straighten it with a wood mallet and cup block, not so much. My blades, by and large, are large and thick. This on eis not "delicate" Quote Link to comment Share on other sites More sharing options...
Quenchcrack Posted February 23, 2009 Share Posted February 23, 2009 You heated it to black????? It should have been a visible red at non-magnetic. Maybe you are just not getting the thing hardened? Thermal shock, not associated with a transformation to martensite can cause distortion. Also, if the cable is made of low and high carbon steels, you need to austenitize to a higher temperature to get the low carbon steels to transform to austenite prior to the quench. Quote Link to comment Share on other sites More sharing options...
Steve Sells Posted February 23, 2009 Share Posted February 23, 2009 I have to ask, how did you determine it was at non magnetic? I hope you didn't place the magnet there till it fell off. heat will ruin a magnet. We only touch it with the steel at various times until it won't attract anymore. Quote Link to comment Share on other sites More sharing options...
rsilver4 Posted February 24, 2009 Share Posted February 24, 2009 You should have normalized the blade a couple of times before the quench,if you get any warping you can straighten then.To normalize heat to orange or non-magnetic and let cool to black---Regards Butch Quote Link to comment Share on other sites More sharing options...
CBrann Posted February 26, 2009 Author Share Posted February 26, 2009 I work outside, so the temp for non magnetic is not very bright on a summer day. No I don't leave the magnet on the piece being tested. Just touch it to check if it sticks, and dunk in the slack tub to keep cool. I see I have a laundry list of things to correct this .... Cool thanks... If i can ever get it straight...etching will be up next... 1 issue at a time Quote Link to comment Share on other sites More sharing options...
TheGreenMan Posted March 7, 2009 Share Posted March 7, 2009 Not to steal this thread but can you use any of the cable you find in Homedepot/Lowes for a cable knife? Quote Link to comment Share on other sites More sharing options...
CBrann Posted March 9, 2009 Author Share Posted March 9, 2009 Not to steal this thread but can you use any of the cable you find in Homedepot/Lowes for a cable knife? I would say yes... with a couple of caveats... it needs to be steel cable... not stainless... NON GALVANIZED!!!.... see sticky on zinc fumes if you have questions... Also needs to be IWRC or independant wire rope core!!!.. there are some cables... actually steel wire rope.... that have a hemp/manilla core, plastic core..... other things as the core.... so thats kind of important.... As for the wrap or diameter.. bigger diameter is better, becasue it decreases in size about 1/3 to 1/2 when welded..... twist is not important to me.... except that when you hit it hot the cable likes to unwrap..... Also smaller strands make a finer pattern..and easier welding.... smaller strands equalls less airspace in the cable Quote Link to comment Share on other sites More sharing options...
John Martin Posted March 10, 2009 Share Posted March 10, 2009 Try quenching in a different medium possibly. Also if you can see how it twisted, try to put some pre twist in it, in the opposite direction slighty, so that when you quench, it will re-align itself. One of the bladesmiths that I talk to frequently, sometimes has to do that with cable knives or a knife that has a lot of twisted damascus in it. Quote Link to comment Share on other sites More sharing options...
tribal forge Posted March 22, 2009 Share Posted March 22, 2009 i found that if the warp, sometimes it is caused by forging to much on one side, i had a cable blank that I forged, and it was looking good, right up till i hardened it, then it bent almost in a "U" my son told me he watched for a bit and i forged more on one side than the other! But he was afraid to tell me! I told him, if I mess up forging like that again to tell me so I can correct it! Quote Link to comment Share on other sites More sharing options...
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