HWooldridge Posted November 27, 2011 Share Posted November 27, 2011 How many of you are experiencing problems with junk hot rolled steel? I know everything these days is primarily made from melted down cars but quality seems to be all over the place. I was splitting some 1/2"x3/16" flat A36 today on the vertical band saw; everything was going copacetic then zzzzzip...all the teeth points stripped off the saw blade about 2 inches into the 4th cut. I didn't want to ruin another bandsaw blade so I tried a new sawzall blade on the same cut and ruined that too. Whatever was inside that steel was pretty hard - I assume some form of carbide. I eventually played blacksmith and just split it hot... :P Quote Link to comment Share on other sites More sharing options...
Glenn Posted November 27, 2011 Share Posted November 27, 2011 I tried to cut some bed rail and tore the teeth out of a hacksaw blade, stripped the teeth points from a sawsall blade and finally used the hot saw. Tough stuff. Granted bed rail is different from A36 but still .... Quote Link to comment Share on other sites More sharing options...
Timothy Miller Posted November 27, 2011 Share Posted November 27, 2011 I tried to cut some bed rail and tore the teeth out of a hacksaw blade, stripped the teeth points from a sawsall blade and finally used the hot saw. Tough stuff. Granted bed rail is different from A36 but still .... Bed rail is ofter rerolled RR track. I learned this from a guy who manufactured bed frames. That is why a relativity small size of angle can support the weight of one or more persons, doing things we are not allowed to talk about on a family web site. Quote Link to comment Share on other sites More sharing options...
Ten Hammers Posted November 27, 2011 Share Posted November 27, 2011 In the past 10 years or so I have experienced a few strange things in steel. Some in bar, some in sheet. Some cold ( drilling ) some hot (forging). Sometimes hard spots, sometimes a spot that actually just melted away ( forging sheet ). These are things I did not experience in my youth with common steel ( read hot or cold finished steel) although I have seen some weird things with old AG steel from time to time). Things change. 20 years ago 14 ga sheet was roughly .080 and barely fit in the 14 slot of the guage tool. Today all I can find is 14ga that mikes 15 (loose) and measures .068-.070. Most of it is pretty good steel though. This of course is not about quality. A sheet of 14 should be 100 lbs. and if you take a million sheets and lose a few ounces on each the margin of profit is changed LARGE. Quote Link to comment Share on other sites More sharing options...
Frank Turley Posted November 27, 2011 Share Posted November 27, 2011 I've also noticed that an occasional supposed rectangular section will be a parallelogram. And sometimes you'll get a small rib along the length looking like a parting line (?). Worn rolling mills will also give quite soft corners on squares and flats. I know that these kinds of stock can be refused on the loading dock or sent back with the delivery truck, but often you're so busy with so many lengths that you don't see them right away. Quote Link to comment Share on other sites More sharing options...
macbruce Posted November 27, 2011 Share Posted November 27, 2011 Saw speed? Teeth per inch? Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted November 28, 2011 Share Posted November 28, 2011 Bed rail often makes good corner chisels! (check your individual rail of course...) Quote Link to comment Share on other sites More sharing options...
SmoothBore Posted November 28, 2011 Share Posted November 28, 2011 Sadly, "inclusions" have always been with us. But the increased proportion of "recycled" material, combined with the nonexistent quality standards for imported steel, has certainly downgraded the overall quality of currently available material.Get used to it ..... . Quote Link to comment Share on other sites More sharing options...
HWooldridge Posted November 28, 2011 Author Share Posted November 28, 2011 Saw speed? Teeth per inch? 14t raker, 120 fpm. Blade cut fine until I hit this one spot in one piece of steel. Quote Link to comment Share on other sites More sharing options...
Raymond Sauvage Posted November 29, 2011 Share Posted November 29, 2011 I have also experienced hard spots in hot rolled mild steel here in Norway. I gues the steel economy is international so we get the same steel all over the world. I have typical run in to problems when teaching students to forge arowheads. When finished forging they usualy quench the workpiece in the slack tube from yellow heat (eaven though I tell them to lett it air cool). Later when they grind and files the profile and bevels on the arow head blade, they run into hard spots that can't be filed. What hapends is that some spots in the steel hardens when quenching in the slack tube. This proves that the carbon content is not well distributet in the stock, and there are spots with high enough carbon content to harden when quenshed. Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted November 29, 2011 Share Posted November 29, 2011 Having worked some *old* steel; it could be pretty skanky too---hot short, cold short, etc and old wrought iron could be anything from smooth as silk to stuff that seems to be 25% slag that wants to fall apart at heat until you weld it up a couple of times. I think that it was fairly recent times that we had good clean steel and we got spoiled. The old books talk about testing every piece that came in the door and allotting it for different tasks depending on that test. But yes I do miss the 1018 and 1020 freely available with no premium! For thin things like arrowheads it is possible to carburize them in places especially if a student overheats it in a reducing zone too. Something I would consider a possibility more than that much of a difference in that little of a space. Have you though of hiding the quench tank when they are working on them? Quote Link to comment Share on other sites More sharing options...
moderator19 Posted November 29, 2011 Share Posted November 29, 2011 I've hit hard spots before in metal but my current steel supplier has good consistant stock steel. They have what is classified as "scrap" and it is an unknown grade of metal. I got one super bad batch out of that once, but it usually is pretty good. All-in-all though, my source of hot rolled stock is good. Quote Link to comment Share on other sites More sharing options...
territorialmillworks Posted December 4, 2011 Share Posted December 4, 2011 One of my 'pet' peeves is angle iron that's not 90 deg. Seems to vary from truck load to truck load at that local supplier. Not their fault. I now take a square with me when I'm making picture frames or shadow boxes. Quote Link to comment Share on other sites More sharing options...
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