Cut To Length Steel And Random Bar Lengths

Some time ago we posted an article about random bar lengths. The attention from that blog contributed to this follow-up about cut-to-length bars. More importantly, how that term differs from random (rdm) bar lengths.

Random bar lengths can be anything the distributor deems beneficial to his selling of the steel bars in  his, or her, inventory. It is most common in the general steel marketplace to see random bar lengths listed as 10/12ft rdm, stainless bars were often listed as 11 to 14ft rdm. You might say that is more less the default in the industry. However, even that category does not define exactly what might be shipped to you. You may get a 13ft bar, or even a 16ft bar; depending on what the distributor has on the floor at the time. In rare instances you may get an 8ft bar or 9ft bar, although shipping a shorter bar is not all that common. The practice of offering random bar lengths can be a very good thing. You should be able to save money on the purchase, less than the higher cost of requiring a bar to be cut to a specific length. Just make sure you and the seller are on the same page at the point of inquiry.

Cut-to-length bars are just that; bars are cut to the exact length you require. You just need to be clear in expressing your requirements; and include a length tolerance that works for both parties. For many decades “plus 1/8″, minus 0” was quite common, and the default if nothing was specified. It pays to be sure both parties understand the same requirement. Especially if it is a first time order or a new vendor or customer. Your expectations understood by one supplier may be lost on the new supplier.

There are other concerns that may affect your order regarding cut-to-length. You may want to specify “No Mill Ends”, or, “Trim Mill Ends”. Mill ends (the original ends of the bars as they were shipped to the distributor from the steel mill), may have been trimmed at the mill, and just fine. They may also be sheared, in which case there may be a slight taper to the end of the bar. The diameter at the bar end may be a bit undersize. It may not be a square cut. It may be slightly dished, it may have identification stamped into the end. If you have not allowed some trim stock to the length you ordered, this may be an issue. It is not a major issue on most orders, but it is worth mentioning if it could be.

If the type of cut required is to a very close tolerance you may want to specify “Square Cut Ends”, and then the tolerance you require. There may be additional charges depending on how specific your needs are.

Very small diameters (those under 5/8″ Dia.) may require special dialogue or instructions if your expectations are exacting. Can the vendor bundle and cut? Once again, there could be additional charges incurred. Very large diameters (over 10″Dia.) usually require a little extra stock be left on the cut. Depending on the size and the intended use, some people will leave 3/8″ or 1/2″ on the cut. Chromed bars often come with “masked areas” at the end of mill length bars. That is an area that has not been chromed. It may be several inches. If you typically purchase full mill random lengths of chrome bars from one supplier, you may want to insure both you and your new supplier understand the specific bar mults of the finished shafts you intend to make. Discuss “trimmed ends” at the point of inquiry.

Newer saws and better saw blades are able to cut phenomenally close these days. There seem to be blades for nearly every metal and hardness. But, just because the saw and the blade can cut close, does not mean that’s what you will be getting. Communication goes a long way to avoid a mishap. Remember; “When it goes bad, who’s wallet comes out?”

-Howard Thomas, June 21st 2019

Bending Steel

There is a famous saying; “A man must know his limitations.” I am sure it is also appropriate for a woman. So it is with this topic. Some steel grades can be bent fairly easily. And, some steel grades in some conditions should never be bent. Before attempting to bend steel you must fully understand its limitations. If you are one of those who never reads instructions and just charges ahead, then there is another appropriate quote from the same person; “Do you feel lucky, kid? Well, do you…?”

The thing is, bending steel is dangerous, even steel listed as “formable”. Ideally, it should be left to experts. But, if you are going to do it anyway, you must know some things about the metal you are contemplating bending. The grade and internal cleanliness are important. But more important is the hardness and the depth and uniformity of that hardness. Soft malleable (ductile) steel in a very light gage may take a nice bend simply by “hand”. Harder (heat treated) heavier gage steel may require high capacity sophisticated equipment that has built-in protections for the machine operator. Very hard steel may not tolerate even the slightest bend, or even pressure for that matter. To put it in perspective, when you think of very hard steel, think of a pane of glass. You wouldn’t push the center of a large pane of glass to see if it bends. At least I hope not. When hard steel fails during a bending process, it literally explodes! As in, loud noise and a section of the roof leaving the building rather quickly.

Before you attempt to bend a piece of steel say this out loud three times; “This is an angry piece of steel that doesn’t want to be played with, and there is a reason why everyone behind me is stepping back.” Then step into your safety gear, study everything you can about the steel, then call a person who bends steel professionally. If that is just not possible and you are required to bend it yourself, do some serious research before you begin and remember, wear appropriate safety gear. Bending steel is not a job for amateurs. Use certified/qualified expert technicians.

Some key words that may help you discover a bit about bending steel are listed below:

Forming, Press Brake, Rolling, Open Air Die, Bottom Die, Bullnose Die, Arc, Degree of Arc, Knife Die (as in; don’t use this type of die), Degree of Bend, Radius of Bend, Hardness HB, Hardness RC, Decarb Removal, Surface Preparation Steel, Brinell, Rockwell, Plasticity, Plastic Deformation, Spring-Back, Work Hardening, Heat Treating, Surface Hardness, Through Hardness, Gushing Head Wound, Depressed Skull Fracture, Life Insurance

4T, 8T, 12T relate to how many times you multiply the thickness of the steel to determine a suggested minimum bend radius. 4T would require a radius of four times the thickness, 12T would be twelve times the thickness, etc.

And, one more famous quote; “Don’t try this at home!”

-Howard Thomas, June 4th 2019

What is Lean Duplex Stainless Steel?

So, what is Lean Duplex Stainless Steel? When and where would you use it? A big topic for a short article. This is merely a brief introduction. Perhaps it will encourage further investigation. Also, we are referring here only to solid round bar, sheet and plate.

For many decades, Austenitic Stainless Grades dominated the industrial and commercial marketplace. They provided excellent general corrosion resistant properties. Then, hardenable martensitic grades began to see usage where increased strength was required. The successful combination of the grain types (Austenite and Ferrite) into one steel introduced Duplex Stainless Steel. Duplex grain structures allowed the broadest utilization of the properties of each. The initial concept was not terribly new; having been introduced about 80 years ago. LEAN DUPLEX stainless steels were the offspring of that product. Early improvements to the Duplex grade involved the enrichment of chemistry of the initial Duplex grade creating upgrades called; Super Duplex and Hyper Duplex; elevated property products with elevated price tags. A significant nickel shortage in the late 1960’s sent engineers scrambling to reverse the “richer is better” trajectory. They embarked upon a project that would minimize the expensive elements in the steel to lower the cost. Minimizing the content of key elements was expected to likewise minimize effectiveness. That was acceptable provided any new grade was still effective in combatting corrosion (specifically Stress Corrosion Cracking, or SCC) and increasing strength over the levels provided by the Austenitic and Martensitic grades used prior to the inception of Duplex.

The resultant steel was Lean Duplex (LDX). It was leaner and cheaper by a long shot. The great surprise was that the resultant loss in corrosion resistance and strength was not as significant as was anticipated. In fact, it was minimal for most intended service applications.

Fairly quickly, the LDX grades enjoyed overwhelming acceptance in the global manufacturing of various tanks, vessels and tubing. So much so, that it is rare these days to find any of those items that do not contain some percentage of Lean Duplex Stainless Steel. What was not readily apparent was the huge potential for daily use as upgraded replacements for the myriad of mundane, and unheralded daily maintenance wear parts and widgets that represent the lowest rung on the maintenance metals food chain; the gremlin maintenance parts that bend and pit and wear. The parts that won’t disassemble because of galling.

My opinion: Lean Duplex shafting, sheet and plate is under-used as a maintenance material. It needs a publicist, promoter or talent agent. Some gnarly champion that might say; “You can use that sh..t on anything!”

It’s that good. Why, it’s the Ginsu knife, the Veg-O-Matic of stainless shafts.

the lean duplex grades are stronger than the austenitic grades of 304 and 316. In my opinion they are generally better grades than 410 and 416. But wait, there’s more, Lean Duplex resists Stress Corrosion Cracking in Sour Service Applications. Since it will most likely be non-similar to your current stainless grades and because it will most likely have a different hardness, it is not disposed to gall. Plus, it is stronger and easier to machine.

Conclusion & Sales Pitch: Associated Steel is one of the few service centers that carries Lean Duplex (ASC2250® LDX) in long shafts they will cut to size. They also carry IN STOCK two different shaft finishes; Fine Turned Oversize “the size will make the size” resulting in less machining and less wasted material, and a Precision polished finished guaranteed bearing fit. Try it! Inquire on hi-def plasma cut parts from plate. Make maintenance life a little easier. Note: Your particular maintenance application has unique characteristics. Always refer to published material information sheets for qualification. 

-Howard Thomas, May 6th 2019

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Howard Thomas

Howard Thomas

Experience

Sr. Acct. Mgr. (US Southwest) / Metallurgical Consultant
Associated Steel Corporation
Jan 2017 – Present

Past Vice President / General Manager
Associated Steel Corporation
Apr 1998 – Jan 2017

Past Vice President / General Manager
Baldwin International
Apr 1974 – Mar 1997

Education

Cleveland State University
Kent State University
University of Denver

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