Case Hardened 1018 vs Heat treated D2

admin

I know case hardening 1018 is about 10x more expensive than heat treating D2, but the materials and machining is so much cheaper for 1018 I'd save a lot of money on that end. But is there a big difference between the 2 once they're hardened? It will be used as a small sheet metal shear, shearing up to 20ga, 3" wide for a specialty application. Or does anyone know of a better option? D2 was what was recommended to me by my tool steel company.John 3:16(2) Miller Pheonix 456(2) Millermertic 252Dynasty 210DXHobart 210MVPDoringer D350 SA Cold SawScotchman 350LT Cold SawWebb 10x50 MillWebb 15x40 LatheGeka Bendicrop Ironworker
Reply:http://en.wikipedia.org/wiki/Tool_steelSynchrowave 300   Old but reliable
Reply:I don't think case hardening would make a good shear blade.  It is only a surface treatment.  Think of an eggshell, a hard shell, soft interior.
Reply:D2.http://www.practicalmachinist.com/vb...blades-195922/"USMCPOP" First-born son: KIA  Iraq 1/26/05Syncrowave 250 w/ Coolmate 3Dialarc 250, Idealarc 250SP-175 +Firepower TIG 160S (gave the TA 161 STL to the son)Lincwelder AC180C (1952)Victor & Smith O/A torchesMiller spot welder
Reply:I wouldn't recommend the 1018 for a shear blade.  A lot depends on expected/intended service life.   I am confused, why would the expense of machining be much of a factor for a 3" wide shear blade?  A2 would also be a candidate,  which should be cheaper.
Reply:@ Econdron - cold shear, light gauge material --> D2.  Ref, http://web.archive.org/web/200611210...cs/Tsb-093.pdf"Discovery is to see what everybody else has seen, and to think what nobody else has thought" - Albert Szent-Gyorgyi
Reply:Originally Posted by Teggy1I wouldn't recommend the 1018 for a shear blade.  A lot depends on expected/intended service life.   I am confused, why would the expense of machining be much of a factor for a 3" wide shear blade?  A2 would also be a candidate,  which should be cheaper.
Reply:I guess you will need more information.  "Excessive tool wear" could be caused by several factors.  What is the current shear made of now?  Are these "shears" in a die set (this is what I'm thinking being only 3"), if so, are the pins and bushings in good order?  Is the material dirty or dusty?The carburizing process would not be a significant factor in material growth.  It is a chemical process, where a carbon rich material off gases, and infuses the surface of the part to be hardened.  Regardless, this would not be a superior product to previously mentioned tool steels.All components should be appropriately ground/machined post heat treat.  Appropriate clearances should be maintained for its respective material thickness, and could be a source of poor service life.  A light oil film applied to the material could also improve service life. Too many possibilities to consider given the limited information.   In the end, you get what you pay for.  All tool steels/alloy steels machine slower than low carbon steel.  You can save money/time now, or later.  Downtime is generally more costly than quality parts.
Reply:A cutting blade?  For a sheet metal shear?Hardened tool steel, without a doubt.  Possible choices off the top of my head would be D2, A2, M2, S7, or similar.Case-hardened mild steel has its uses/places, but this really ain't it.And yeah, tool steel are 'tougher' to machine than mild steel or free-machining steels (btw, don't make a cutter blade out of a free-machining steel).  Even in the 'soft' condition, the tools steels are tougher to machine than plain mild steel.  Hopefully the machinist(s) are using the correct speeds and feeds for machining the tool steel pieces and not just trying to use the same speeds/feeds as for mild steel.  The best laid schemes ... Gang oft agley ...
Reply:I've been making and selling these for a while now, I've just been looking for ways to cut costs down. I attached a picture of the last 15 I did. The dies are currently made from D2 and I'm sure the machinist has been machining them correctly. However, there is no post heat treat machining. The dies are tempered at just over 900*F to eliminate contraction.John 3:16(2) Miller Pheonix 456(2) Millermertic 252Dynasty 210DXHobart 210MVPDoringer D350 SA Cold SawScotchman 350LT Cold SawWebb 10x50 MillWebb 15x40 LatheGeka Bendicrop Ironworker
Reply:What is the clearance per side?  I want to say about 10% of the material thickness,  but I'd have to check the books.  That would be about .0036" per side.  It would help to see the failure mode,  and know how many parts are being run before deemed worn.
Reply:1018 does not seem like it would have enough carbon to harden enough to make a good blade and spheroidized tool steels are generally very easy to machine prior to heat treatment.  None of this makes a lot of sense.  If I remember correctly steels under 1020 are really considered not heat treatable because they do not have enough carbon.Last edited by 76GMC1500; 05-29-2014 at 09:43 PM.
Reply:I think steels under 1040 is where the line is drawn, but I could be wrong. I guess I had just assumed 2 pieces of metal both hardened to 62HRC would be the same thing? That's why I asked the question.John 3:16(2) Miller Pheonix 456(2) Millermertic 252Dynasty 210DXHobart 210MVPDoringer D350 SA Cold SawScotchman 350LT Cold SawWebb 10x50 MillWebb 15x40 LatheGeka Bendicrop Ironworker
Reply:Originally Posted by EcondronBecause they're doing 100 at a time and are experiencing excessive tooling wear, and it takes longer to machine. From what I'm told anyway.... Even though they're machining the metal pre heat-treat, it's still much tougher than mild steel.And after I posted this, I was thinking case hardening in a sense actually adds a hardened surface to the piece. It may only be .004", but I think that would be enough to make these things not fit together properly. I'll check into A-2 and see if there's any cost savings. Anyone have some good sources for tool steels?? I'm getting the bars drop shipped anyway since the machinist is about 4 hrs away.