Greenbeast Posted October 31, 2013 Share Posted October 31, 2013 I'm making some door/drawer pull handles. I'm using 10mm square stock. Using the rounded edge on my anvil i neck in 10mm from the end of the bar and go quite thin (~3-4mm) then draw the taper back. this leaves me a lump i can squish for the screw hole. As i'm finishing up the taper i'm finding the transition at the neck to be splitting. What's causing this, what can i do to stop it? I tried doing the second pair hotter which i think may have helped, do i need to go hotter still? Many Thanks Quote Link to comment Share on other sites More sharing options...
Steve Sells Posted October 31, 2013 Share Posted October 31, 2013 I am not sure what steel you are using, but drastic transitions can cause stress in the metal. Rather than reducing the cross section all at once, try a smaller reduction allowing the steel to reheat before taking it down the remaining thickness. If its stress this should reduce that a bit. Quote Link to comment Share on other sites More sharing options...
Greenbeast Posted October 31, 2013 Author Share Posted October 31, 2013 It's mild steel, dunno what that would translate to exactly for you guys. That is worth a go, thankyou! Quote Link to comment Share on other sites More sharing options...
swedefiddle Posted October 31, 2013 Share Posted October 31, 2013 Good Morning, Normally splitting is caused from working too cold. If you forge a taper at the transition first, before you start drawing it out, the outer layer of the work will be expanding to a taper instead of a shoulder. Just a thought. Neil Quote Link to comment Share on other sites More sharing options...
doc Posted October 31, 2013 Share Posted October 31, 2013 By splitting do you mean a length wise split or a crack that is perpendicular to your cross section? If in fact it is the latter it's probably do to taking too many heats to accomplish your tapering. Get the metal hot and hit it faster and harder. :) Quote Link to comment Share on other sites More sharing options...
Joel OF Posted October 31, 2013 Share Posted October 31, 2013 It could be the steel rather than a fault in your method. I'm told that mild steel nowadays is a load of junk, especially the foreign imports, try a supplier that stocks British mild steel & see if you get better luck? Quote Link to comment Share on other sites More sharing options...
Greenbeast Posted October 31, 2013 Author Share Posted October 31, 2013 doc - a split perpendicular. That sounds possible. I will have another 'crack' at this tomorrow and see what i can do. Quote Link to comment Share on other sites More sharing options...
Steve Sells Posted October 31, 2013 Share Posted October 31, 2013 try a supplier that stocks British steel & see if you get better luck? I like Rob Halford too , but how will that help the cracking? I didnt think about making sure you are at correct temperatures. Good points guys. P.S. I could not resist the JP joke... :blink: Quote Link to comment Share on other sites More sharing options...
PaulKrzysz Posted October 31, 2013 Share Posted October 31, 2013 If the edge of your anvil is too sharp, it will cause stress in the piece, so will working it too cold as another member mentioned. Just do not work it too cold, and use the filed radius of your anvil! Quote Link to comment Share on other sites More sharing options...
Ten Hammers Posted November 1, 2013 Share Posted November 1, 2013 yes on the cold worked ( sounds like you knew this ). Am curious if the steel you are using is hot or cold rolled. Sometimes cold finished ( keystock) can be grumpy. YES newer steel is sometimes substandard. Quote Link to comment Share on other sites More sharing options...
arkie Posted November 1, 2013 Share Posted November 1, 2013 I was fullering notches in 3/8" x 3/4" hot rolled mild steel bar to draw out my reins on some tongs. Hammered the work too cold (colder than dark red) and had cracks on every fuller notch. :( Quote Link to comment Share on other sites More sharing options...
Greenbeast Posted November 1, 2013 Author Share Posted November 1, 2013 Ok thanks for the input guys, i'm going to make sure i get them back in the fire sharpish today Quote Link to comment Share on other sites More sharing options...
Dave Budd Posted November 1, 2013 Share Posted November 1, 2013 i've had stock with cold shuts rolled into them. Whole 6m lengths have had a crease running down their lengths and only show up when i start forging. If the problem persists with other dimensions of stock, then chances are you are working too cold. Quote Link to comment Share on other sites More sharing options...
Joel OF Posted November 1, 2013 Share Posted November 1, 2013 If you're necking in & tapering offset to one side & then centreing everything afterwards instead try necking in with a top &:bottom fuller. Less stress on the steel when it's very thin. Quote Link to comment Share on other sites More sharing options...
Frosty Posted November 2, 2013 Share Posted November 2, 2013 Heat or a too sharp a shoulder top my list of probable causes. Off the top of my dented head that is. Inconsistent steel is next down the list, after a couple few tries you ought to be able to figure out the working temp for whatever you have at hand, or that it just isn't forgeable. Learning the feel of steel is an acquired skill as is failure analysis so you can tell what's going wrong or right. Therre is a lot of forged steel that isn't forgeable at our level, say rampable, controlled atmosphere furnaces, REALLY hard hitting power hammer, press or forge roll, etc. some metals are just too specialized for the home shop. Failure analysis; I've been trying to figure out what went wrong with that one all my life, just part of the game. <wink> Frosty The Lucky. Quote Link to comment Share on other sites More sharing options...
Greenbeast Posted November 2, 2013 Author Share Posted November 2, 2013 I'm pretty sure it went better the next morning, but i mucked up a twist right at the end and threw the thing into the corner of the workshop :lol: I think i had been making the mistake of keeping it out of the fire too long Quote Link to comment Share on other sites More sharing options...
Borntoolate Posted November 3, 2013 Share Posted November 3, 2013 I think have done what you are talking about myself. Often looks like numerous cracks going perpendicular to the length at the narrow transition. My belief it is caused by. Letting this area get to cold while working other areas near by. This area gets yanked around a bit if your hammer blows are not perfect and true between both hammer and anvil. Even then it is going to get pulled, vibrated and tugged and stressed causing cracks in the direction you are seeing. Working this area to cold. Letting this area hang off the far edge while cold but working behind it on the anvil. This thin area hangs off the far edge and vibrates or whips about causing cracks. Too many heats maybe but I think that is a symptom of one of the above. You should be able to get where you need to go with a couple heats on this one. Others would probably do it in one I am sure. :) Depending on how detailed and elaborate. Rather than work this down to it's finished cross section you could just begin this area, established the thinner area and section it out then come back to it. Heat will be against you since this area will cool fast. I think the solution is as above. Fewest heats possible without working cold, fewest heats reduces the number of hammer blows and therefore stress cycles. Don't let this area get cold. Work thin transitions last or late if at all possible. Don't let the thin area whip or vibrate while working other areas. Changing type of steel might have some impact but I think the above is most important. Did you cracks look anything like this? '?do=embed' frameborder='0' data-embedContent>> One other thought. Even if you don't see a crack or don't have a complete failure you have to believe that cracks are forming under above conditions. So avoid the above in order to preserve the long term integrity of your project. My two cents based on info from this site and my interpretation of past personal failures (Also called learning!). I am fine with failure as long as there is learning! Quote Link to comment Share on other sites More sharing options...
John McPherson Posted November 3, 2013 Share Posted November 3, 2013 George Dixon did a seminar a loooong time ago that I attended. He was splitting branching elements out of a flat bar and working them into leaves, etc. One of the things he said that stuck with me is that you have to get a forging heat on the entire element down into the parent stock to keep the neck from breaking off. Steel can be more brittle at a black heat than at room temperature. Quote Link to comment Share on other sites More sharing options...
Greenbeast Posted November 3, 2013 Author Share Posted November 3, 2013 Thanks guys Borntolate i think you're spot on there. I will take heed of this advice when reattempting the piece Quote Link to comment Share on other sites More sharing options...
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