How is the single weight of the Automotive Wiring Harness Protection Sleeve calculated?

Automotive Wiring Harness Protection Sleeve are sold to customers by the meter or by the strip. Some customers will ask what size it is and how much it weighs when asking for a quotation. The weight industry is called "single weight", and the so-called single weight is normally Refers to the weight of one meter in grams. In addition, if it is according to the article, you need to know the length and then convert it. The following example illustrates:

Zhang San needs 500 meters of Automotive Wiring Harness Protection Sleeve with an inner diameter of 12 and an outer diameter of 15. First, confirm the single weight. Professional Automotive Wiring Harness Protection Sleeve manufacturers calculate in this way, subtracting the square of the inner diameter from the square of the outer diameter is one meter. The unit weight is 15*15-12*12=81 grams, then some customers will say that the total weight of 500 meters is 40.5KG, why the goods received are less than 40KG, in fact, this is the case, Automotive Wiring Harness Protection Sleeve Because the sleeve is extruded, there will be a tolerance range for human control during the extrusion process, such as 12-15, there is a tolerance of plus or minus 0.2 mm, as long as the inner diameter of the tube is 11.8-12.2, and the outer diameter is 14.8- 15.2 are all qualified, the unit weight is only a standard reference for our judgment during production, and the actual weight shall prevail.
If needs 500 strips with a length of 120MM, then the weight of a single strip should be 81*0.12=9.72 grams. The above is for ordinary round pipes, which can be calculated and measured according to this method. Other silicone rubber products with irregular shapes, such as special-shaped strips and sealing rings, need to be calculated according to the drawings.