Cool Hand Posted October 27, 2009 Share Posted October 27, 2009 I know density can impact the wieght, just looking for a rough estimation of what 1 square inch of metal weighs. I find a lot of good junk, but sometimes have no idea what weight is because I have no scales handy. I probably get overcharged quite a bit because of that sometimes. Either wieght or a good formulaic approach would be handy. I appreciate the input, Cool Hand Quote Link to comment Share on other sites More sharing options...

Nakedanvil - Grant Sarver Posted October 27, 2009 Share Posted October 27, 2009 A "square inch" can weigh anything, depends on thickness. Weight is from "cubic inches". A cubic inch is steel is about .283 lb. 1/4 plate is about 10 lb per square foot, so 1" plate is about 40 lb per square foot. Width X length X thickness = "N". 1/4 x N plus a little (10%) is close to the weight. Quote Link to comment Share on other sites More sharing options...

Cool Hand Posted October 27, 2009 Author Share Posted October 27, 2009 Thanks for the correction. i will definitely try your formula. Quote Link to comment Share on other sites More sharing options...

Francis Trez Cole Posted October 27, 2009 Share Posted October 27, 2009 most of the metal suppliers have calucators on there websights. My supplyer offers a book I pick up one the last time I bought steel. It has weight by size by the foot. King articheture metals has it listed on there web sight. Quote Link to comment Share on other sites More sharing options...

Cool Hand Posted October 27, 2009 Author Share Posted October 27, 2009 I buy primarily from junk dealers, flea markets, and roadside vendors. Only 1 metal supplier here locally and I save them for the high end stuff. Quote Link to comment Share on other sites More sharing options...

John B Posted October 27, 2009 Share Posted October 27, 2009 I use hand held spring balance type scales one large and one small, I find it easy then to weigh the complete item (or parts and add them up) to know what to charge the client for the materials content of the job. They are also handy if someone just wants to buy some steel off me Quote Link to comment Share on other sites More sharing options...

Nakedanvil - Grant Sarver Posted October 27, 2009 Share Posted October 27, 2009 Well YEAH, but none of those help when you're standin' in the junkyard with a piece of steel in your hand. I thought that was the question. Quote Link to comment Share on other sites More sharing options...

rthibeau Posted October 27, 2009 Share Posted October 27, 2009 1 cubic inch of steel (1"x1"x1") weighs 0.2835 lb; 1" sq 12" long weighs 3.4032 lb; 1/2" sq 12" long weighs 0.8508 lb; 1/4" sq 12" long weighs 0.2127 lb. 1" round 12" long weighs 2.6729 lb; 1/2" round 12" long weighs 0.6682 lb; 1/4" round 12" long weighs 0.1670 lb. Write all that down on a 3x5 card and take a measuring tape with you to the junk yard, you can figure out the weight of pieces of steel. Quote Link to comment Share on other sites More sharing options...

Pault17 Posted October 27, 2009 Share Posted October 27, 2009 I copied this down from somewhere a while ago. I don't remember the source, but am pretty sure it is from here. I actually keep it in my pda for quick reference (my welding teacher thought it was a "hoot" and wanted a copy) it is long, but worth it, i think Geometry for the Metalsmith - find the circumference of a circle: Multiply the radius by 6.2832 or Multiply the diameter by 3.1416 or Multiply the square root of the area by 3.5449 - find the radius of a circle: Multipy the diameter by 0.5 or Multiply the circumference by 0.15915 or Multiply the square root of the area by 0.56419 - find the diameter of a circle: Multiply the radius by 2 or Multiply the circumference by 0.31831 or Multiply the square root of the area by 1.1284 - find the area of a circle: Multiply the square of the radius by 3.1416 or Multiply the square of the diameter by 0.7854 or Multiply the square of the circumference by 0.07958 - find the area of a hexagon: Multiply the square of the distance across by 0.86603 or Multiply the area of the inscribed circle by 1.1027 - find the area of an octagon: Multiply the square of the distance across by 0.82843 or Multiply the area of the inscribed circle by 1.0548 - find the area of a rectangle: Multiply the length by the width - find the area of a triangle: Multiply the base by one half the perpendicular height - find the side of an inscribed square: Multiply the diameter by 0.7071 or Multiply the circumference by 0.2251 - find the side of an equal square: Multiply the diameter by 0.8862 - find the diameter of the circumscribing circle of a square: Multiply the side by 1.4142 - find the circumference of the circumscribing circle of a square: Multiply the side by 4.443 - find the cubic contents of a cone: Multiply the area of the base by one-third the altitude - find the area of an ellipse: Multiply the product of its axes by 0.7854 - find the area of a parallelogram: Multiply the base times the perpendicular height - find the volume of a parallelogram: Multiply the area of the cross section times the length - find the surface area of a cylinder: Multiply the length times the circumference of the body plus the area of both ends - find the volume of a cylinder: Multiply the area of the base by the perpendicular height - find the surface area of a sphere: Multiply the square of the diameter by 3.1416 or Multiply the diameter times the circumference - find the volume of a sphere: Multiply the cube of the diameter by 0.5236 - find the capacity of a tank in gallons: (all measurements must be reduced to inches) - For cylindrical tanks, multiply the length by the square of the diameter by 0.0034 - For rectangular tanks, multiply the length by the width by the depth and divide by 231 - For elliptical tanks, multiply the length by the short diameter by the long diameter by 0.0034 - convert Brinell Hardness to tensile strength: Divide the Brinell Hardness number by two to get the approximate tensile strength in thousands of pounds per square inch. Example: Assume a Brinell Hardness of 248. 248 divided by 2 = 124,000 p.s.i. (approximate tensile strength) Conversely, drop the last three figures of the tensile strength and multiply by two to get the approximate Brinell Hardness number. Example: Assume a tensile strength of 122,000 p.s.i. 122 X 2 = 244 (approximate Brinell Hardness) - estimate the weight of a round steel bar: Multiply the diameter by 4, square the product, and divide by 6. The result is the approximate weight in pounds per foot of length. - estimate the weight of a square steel bar: Square the size, add a zero and divide by 3. The result is the approximate weight in pounds per foot of length. - estimate the weight of a flat steel bar: Multiply the width by the thickness, add a zero and divide by 3. The result is the approximate weight in pounds per foot of length. Again, I apologize for the obvious plagerism, but am sincerely thankful for the knowlege shared paul Quote Link to comment Share on other sites More sharing options...

David Einhorn Posted October 27, 2009 Share Posted October 27, 2009 From the book "Practical Mechanics" on a site that provides free ebooks:Rules for Obtaining Approximate Weight of Iron. Quote Link to comment Share on other sites More sharing options...

John B Posted October 27, 2009 Share Posted October 27, 2009 Well YEAH, but none of those help when you're standin' in the junkyard with a piece of steel in your hand. I thought that was the question. Spring balance will fit in your pocket, Quote Link to comment Share on other sites More sharing options...

Cool Hand Posted October 27, 2009 Author Share Posted October 27, 2009 Fantastic information. Remember, what I need is to ensure I am not getting ripped off on the weight of a significant amount of iron. Great stuff so far, thanks. Quote Link to comment Share on other sites More sharing options...

rthibeau Posted October 27, 2009 Share Posted October 27, 2009 then put the bathroom scale in the truck and there ya go....weigh it all.. Quote Link to comment Share on other sites More sharing options...

David Einhorn Posted October 28, 2009 Share Posted October 28, 2009 . I need is to ensure I am not getting ripped off on the weight of a significant amount of iron... Around here you can just call another wholesaler and get a price quote. :) Quote Link to comment Share on other sites More sharing options...

pkrankow Posted October 28, 2009 Share Posted October 28, 2009 Is your spring balance what I would call a fish scale? Phil Quote Link to comment Share on other sites More sharing options...

irnsrgn Posted October 28, 2009 Share Posted October 28, 2009 (edited) when I estimate jobs, I used a steel suppliers weight book, that's how the supplier figures the weigh of the material you buy, and I usually never actually weighed material when I sold it to walk in customers. just use the theoretical weight that is in 40.8/144the books that I had copied to an easy to read chart under the plastic of my desk. but if you remember a few simple things you can figure the weight of anything with a cheap calculator. a square foot of 1/8th or 11 ga is 5.1, 3/16 or 7 ga is 7.5, 1/4 or 4 ga is 10.2 lbs. just figure the square feet, length times width divided by 144 times the weight of that particular thickness of steel, so 1 inch would be 40.8 divided by 144= .2833333333333lbs. times 16, the ounces in a lb, =4.5333 ounces. Edited October 28, 2009 by irnsrgn Quote Link to comment Share on other sites More sharing options...

John B Posted October 28, 2009 Share Posted October 28, 2009 (edited) Is your spring balance what I would call a fish scale? Phil Yes, they come in a variety of weight ranges and sizes, (not all are shiny and silver like a real fish scale what's on a fish) Being a bit thick, I find them much more convenient than bits of paper, books and calculators. Edited October 28, 2009 by John B Quote Link to comment Share on other sites More sharing options...

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