How to calculate the weight of the pipe & tube ??? : Sang Pipe?? : 4,670 1. The formula to calculation of theoretical weight for one meter carbon seamless steel pipes & tube.W=0.02466(OD-WT)WTNote:W--theoretical weight per meter kg/m;OD--nominal diameter mm;WT--nominal thickness mm;2. The formula to calculation of theoretical weight for one meter stainless seamless steel pipes & tube.W=0.02491(OD-WT)WTNote:W--theoretical weight per meter kg/m;OD--nominal diameter mm;WT--nominal thickness mm;-------------------------------------------------------------------------------------------------Steel tube or steel pipes whatever weld tube or seamless tube are mostly sold by weight not for length .it mainly due to the seamless steel tube are made from steel billets and steel billets was sold from iron manufactory via weight not for length . and at the same reason weld pipe are mostly produced by steel strip or steel sheet ,and these two products also gauged by ton .not for its length .unless the steel pipe is a very very accuracy dimension products whose cost for machine of the tube is very expensive and that caused the cost for is material (perform tube ) is occupied a very small portion of its total cost .then the steel tubes can be valued by pieces or by length . So according to our experience ,most tube pipe are sold by ton not for length .some customers from western country have been used to buy tube by length ,they always ask price as how much per meter.Our suggestion is that you can got the quotation by ton and you then concluded the price for per ton . for example if a seller tell you the seamless pipe is guaranteed 1000 meters ,and its total weight is 30 tons .total price is 30000 USD ,then you can know that the price is 1000 USD/ton ,and also you can know that the price also can be regarded as 30 USD/meter . Another problem is if a buyer know that he wants 1000 meters carbon steel pipe ,but how can he know the weight of it weight , commonly due to the density is fixed .So the it is easy to calculate the weight from its dimension . here we can give you a predigested formula. let us have an example for a round shape seamless tube . suppose its outside diameter (OD) is D mm and the wall thickness of the seamless steel pipe is r mm , and its length is L meters ,so we can calculate its bulk and then multiple its density and then you can got its weight . it is easy to know its weight formula is : [p (D/2) ^2-p(D/2-r)^2]*L*? , after predigest ,we can got the final formula is : (D-r)*r*p?*L, due to: ?=7.85 kg/m3 p=3.1415 . and then the formula should be (D-r)*r*L*24.66 But consider the unit for D and r is millimeter not meters ,so final result is : (D-r)*r*0.02466*L .remember the unit for D and r is So if the pipe is weld carbon steel tube ,you can direct use this formula.For example you want a pipe with 48.3MM OD ,2.5MM wall thickness , 6 meters length ,and totally 3000 pcs ,then the weight should be (48.3-2.5)*2.5*0.02466*6*3000=50824 kg , totally about 51tons ,and you also know the goods can be delivery via 2 pcs of 40 ft containers.The story is not over till now , if the pipe is seamless steel tube ,and it comply standard with ASTM A 106 Gr B standard or ASTM A 213 standard ,these two standard is commonly used in boiler industry ,and the tube must bear high pressure ,so the standard need the pipe have positive tolerance for its wall thickness to guarantee that the minimal capability of the tube is larger than its requirement for boiler.In fact the these two standard request the tolerance to be -0/+22% , so the weight is not a fixed data . currently there are two methods commonly used to deal with the problem . the first one is the pipe producer just tell you the price per ton ,and the real value of the goods will be available after the pipe is been produce ,and the weigh the tube and then let you know how much you have to pay . the second methods is that the supplier fixed the weight will 11% higher than its theoretic weight , for example the above mentioned tube is 50.8tons and further more suppose the pipe is seamless steel tube and apply to standard ASTM A 106 Gr B ,and the seller will fixed the tube value based on 50.8*1.11=56.388 tons , if the goods is larger in its weight after it was been produce ,then the seller will bear the risk .if finally the pipe is 53 tons ,then the seller will earn more , if the weight is less than 50.8 tons for example 49 tons ,needless to say the tube is unqualified.Some standard do not need tolerance for -0/+22% ,for example ASTM A 312 and ASTM A 269 , The standard acceptable for negative tolerance ,then the buyer should take care of its weight . So we know that seamless tube have larger tolerance and weld pipe due to the tolerance is according to the thickness of the steel sheet , and steel sheet commonly have small tolerance in thickness ,so commonly weld tube do now have larger tolerance in weight . tube some buyer want to by galvanized steel tube ,then the weigh again will be an issue and need to be talked about . Some buyer need the tube to be hot dip galvanized pipe and ask for the zinc layer must be 50 microns thickness , then how can we know its real weight of the tube , the density of zinc is 7.14g/cm3 , if the thickness is 50 microns then it can also be express as 50*7.14=357g/m2 , so different express methods have the same meaning .Commonly if the zinc layer is small than 320 g/m2 or 45 microns thickness ,then the weight should be 6% higher then the un-galvanized tube ,for example if the tube is 100 tons ,after galvanization the tube maybe be 106 tons . but if the tube made by galvanized steel sheet or galvanized steel strip ,then the tube will not have so much increase in weight .but the tube need to reinforce the zinc in the welding line ,due to welding rod is not galvanized rod ,so the part of seam surface is not galvanized . need to additional process to add zinc in this place .The density of stainless steel pipe is higher than carbon steel .so its parameter is not the same , in the above we mentioned that the weight of the stainless pipe is (D-r)*r*0.02466*L, this formula is for carbon steel tube ,if the pipe is stainless tube then its formula should be as follows: (D-r)*r*0.02491*L , other issue like tolerance is the same as carbon steel tube . If the pipe is line pipe and need 3 PE coating . then the seller quote for price based one the weight of the pipe which is not including the weight of PE coating . for example if the buyer wan to buy 300 meters pipe ,the OD is 1000MM ,the wall thickness is 9MM ,then according to the formula the weight should be 65.98ton ,the price for PE is according to the acreage of the surface of the tube ,suppose the tube is 1000 square meters surface ,the cost for PE is 3000USD, i.e 3 USD/square meter , then the price for PE coating can be regarded as 3000/65.98=45.68USD/ton , add this price to the price of tube ,then we can get the price for 3PE coating steel tube based on pipe weight not including the weight of PE , that means the price is based on bare pipe , the real weight of the goods is larger than 65.98tons.For precision steel tube like hydraulic cylinder ,honed pipe , due to the machine cost is very high , so the price is based on theoretic weight of the pipe or based on meters , the producer will not weight the real weight of the tube . the weight is just used to calculate the value of the goods . If the goods is not steel tube ,it just a steel billet or steel rod ,then you can suppose the wall thickness is the same as radius . then r-D/2 , then you can get the another formula as :D^2 *0.0006165*L. If the pipe is rectangle tube or square tube , you can suppose it was made from round tube , the D can be replaced as ,(border length 1+border length 2)*2/3.14=D, then you can convert the problem into round tube.