The size and weight of the steel

The size and weight of the steel

First, steel length size

The length of steel is the most basic size of all kinds of steel, which refers to the length, width, height, diameter, radius, inner diameter, outer diameter and wall thickness of steel. The legal units of measurement for steel length are meters (m), centimeters (cm), millimeters (mm). In current practice, inches (") are also used, but they are not legal units of measurement.

1. The steel scope is an effective measure to save materials. Range measurement means that the length or length by width is not less than a certain size, or that the length and length by width are delivered in a range of sizes from any number to any number. The manufacturer can produce and supply according to the size requirements.

2. Indeterminate ruler (usually length) where the product size (length or width), in the standard range, but does not require a fixed size called indeterminate ruler. Variable ruler length is also called the usual length (ruler). Metal materials to be delivered on a variable scale shall be delivered within the specified length. For example, ordinary round steel of no more than 25mm, whose length is usually specified as 4-10m, can be delivered within this range.

3. Measuring scale according to the order to cut into a fixed size called measuring scale. When the goods are delivered at the fixed length, the metal materials must have the length specified by the buyer in the order contract. For example, if it is stated in the contract to be delivered at a fixed length of 5m, all materials delivered must be 5m long. Any shorter or longer than 5m will be disqualified. But in fact, it is impossible for all deliveries to be 5m long, so it is stipulated that positive deviation is allowed, and negative deviation is not allowed.

4. The quadruple ruler cut into integral multiples according to the fixed size required by the order is called the quadruple ruler. The length of the metal material to be delivered must be an integer multiple of the length specified by the demander in the order contract (called a single size) (plus saw edge). For example, the buyer requires in the order contract that the length of the single scale is 2m, so the length is 4m when it is cut into double scale and 6m when it is cut into 3 times scale, and one or two saw blades are added respectively. The amount of saw blade is specified in the standard.

Only positive deviation and no negative deviation are allowed in the delivery of the double ruler.

5. The short ruler whose length is less than the lower limit of the indefinite length stipulated by the standard, but not less than the shortest allowable length is called the short ruler. For example, the standard for water and gas steel pipes allows 10 percent (based on the number of pipes) of 2-4m short feet in each batch. 4m is the lower limit of indefinite length, and the minimum allowable length is 2m.

6. The narrow ruler whose width is less than the lower limit of the indeterminate ruler stipulated in the standard, but not less than the narrowest allowable width is called the narrow ruler.

When delivering by narrow yardstick, attention must be paid to the narrow yardstick ratio and the narrowest yardstick as specified in the relevant standards.

Two, steel length size examples

1. Length and dimension of section steel

The standard length of train rails is 12.5m and 25m.

(2) The size of round steel, wire and steel wire is calibrated with the number of mm (mm) of diameter d.

The size of the square steel is calibrated by the number of millimeters (mm) of the side length a.

The size of hexagonal and octagonal steel is calibrated by the number of millimeters (mm) of the opposite side distance s.

⑸ The size of the flat steel is calibrated by the width b and the thickness d of mm (mm).

The size of the I-beam, channel steel to the waist height h, leg width b and waist thickness d of mm (mm) number calibration.

The dimensions of the equilateral Angle steel are calibrated in millimeters (mm) for the same width b and thickness d. The dimensions of non-equilateral angles are calibrated in millimeters (mm) of width B, b and thickness d.

The size of the H section is calibrated in millimeters (mm) of web height h, wing width b and web thickness t1 and wing thickness t2.

2. Length and dimension of steel plate and steel belt

Generally, the thickness of steel plate d is calibrated by the number of mm (mm). The steel strip is calibrated in millimeters (mm) of width b and thickness d.

The sheet steel plate has different sizes, such as hot rolled steel plate: 1mm thick steel plate, width 600× length 2000 mm; 650×2000 mm; 700×1420 mm; 750×1500 mm; 900×1800 mm; 1000 x 2000 mm, etc.

3. Length and dimension of steel pipe

Generally, the outer diameter D, inner diameter and wall thickness S of the steel pipe are calibrated in millimeters (mm).

(2) Each steel pipe has different sizes specified, such as seamless steel pipe with outer diameter of 50mm, wall thickness of 2.5-10mm 15; Or the same wall thickness of 5mm, there are 32-195mm outside diameter of 29. For example, the wall thickness of welded steel pipe with nominal diameter of 25mm is 3.25mm ordinary steel pipe and 4mm thickened steel pipe.

Three, steel weight

1. Theoretical weight of steel

The theoretical weight of steel is calculated according to the nominal size and density of steel (used to be called specific gravity). This is directly related to the length size, section area and size permissible deviation of steel. Due to the allowable deviation of steel in the manufacturing process, the theoretical weight calculated by the formula is different from the actual weight, so it is only used as a reference for estimation.

2. Actual weight of steel

The actual weight of steel refers to the actual weight of steel to weigh (weigh), called the actual weight. The actual weight is more accurate than the theoretical weight.

3. Calculation method of steel weight

(1) Gross weight is the symmetry of "net weight", which is the total weight of the steel itself and packaging materials. Transportation enterprises calculate freight by gross weight. But the steel is sold in the net weight calculation.

⑵ Net weight is the symmetry of "gross weight". The gross steel weight minus the packing material weight, that is, the actual weight, is called the net weight. In the steel purchase and sale generally according to the net weight calculation.

(3) The weight of the steel packing material is called tare weight.

The unit of weight used in freight calculation according to the gross weight of steel. Its legal unit of measurement is ton (1000kg), as well as long ton (1016.16kg in British system) and short ton (907.18kg in US system).

(5) Billing weight is also called "billing ton" or "freight ton". The shipping department charges the freight for the weight of the steel. Different modes of transportation, there are different calculation standards and methods. Such as railway vehicle transportation, generally use the truck marked load as the billing weight. Road transport is combined with the vehicle's deadweight tonnage charge freight. Railway, road, with a few kilograms of gross weight as the minimum billing weight, insufficient into the whole.

Iv. Theoretical weight calculation of steel

The unit of measurement for calculating the theoretical weight of steel is kilogram (kg). Its basic formula is:

W (weight, kg) = F (sectional area mm2) × L (length, m) ×ρ (density, g/cm3) × 1/1000

The density of steel is 7.85g/cm3. The theoretical weight calculation formula of various steels is as follows:

Name (unit) Calculation formula Symbolic meaning calculation example

Round steel wire rod

(kg/m) W= 0.006165 ×d 2 d = diameter mm diameter 100 mm round steel, calculate the weight per m. Weight per m = 0.006165 ×1002=61.65kg

Rebar (kg/m) W= 0.00617 ×d 2 d= section diameter mm section diameter of 12 mm rebar, find the weight per m. Weight per m =0.00617 ×12 2=0.89kg

Square steel

(kg/m) W= 0.00785 ×a 2 a= square steel with side width of mm and side width of 20 mm, calculate the weight per m. Weight per m = 0.00785 ×202=3.14kg

Flat steel

(kg/m) W= 0.00785 ×b ×d b= side width mm

d= flat steel with thickness of mm and side width of 40 mm and thickness of 5mm, calculate the weight per m. Weight per m = 0.00785 ×40 ×5= 1.57kg

Hexagonal Angle steel

(kg/m) W= 0.006798 ×s 2 s= hexagonal steel with opposite side distance mm and opposite side distance 50 mm, calculate the weight per m. Weight per m = 0.006798 ×502=17kg

Octagonal steel

(kg/m) W= 0.0065 ×s 2 s= octagonal steel with opposite side distance mm and opposite side distance 80 mm, calculate the weight per m. Weight per m = 0.0065 ×802=41.62kg

Equilateral Angle steel

(kg/m) W= 0.00785 ×[d (2b -- d) +0.215 (R2 -- 2r 2)] b= side width

d is equal to the edge thickness

R= inner arc radius

r= end arc radius Find the weight per m of 20 mm ×4mm equilateral Angle steel. The R of 4mm ×20 mm equilateral Angle steel found in the metallurgical product catalog is 3.5 and 1.2, so weight per m = 0.00785 ×[4 × (2 ×20 -- 4) +0.215 × (3.52 -- 2 ×1.2 2)]=1.15kg

Unequal Angle steel

(kg/m) W= 0.00785 ×[d (B+b -- d) +0.215 (R2 -- 2 r 2)] B= long side width

b is equal to the short side width

d is equal to the edge thickness

R= inner arc radius

Calculate the weight per m of 30 mm ×20mm ×4mm unequal Angle steel by r= end arc radius. The R of 30 ×20 ×4 unequal Angle steel found in the catalogue of metallurgical products is 3.5 and 1.2, so weight per m = 0.00785 ×[4 × (30+20 -- 4) +0.215 × (3.52 -- 2 ×1.2 2)]=1.46kg

Channel steel

(kg/m) W=0.00785 ×[hd+2t (b -- d) +0.349 (R2 -- r 2)] h= high

b= leg length

d= waist thickness

t= average leg thickness

R= inner arc radius

r= end arc radius Calculate the weight per m of channel steel 80 mm x 43mm x 5mm. It is found in the metallurgical product catalog that the channel steel t is 8, R is 8, r is 4, then the weight per m =0.00785 ×[80 ×5+2 ×8 × (43 -- 5) +0.349 × (82 -- 42)]=8.04kg

I beam steel

(kg/m) W= 0.00785 x [hd+2t (b -- d) +0.615 (R2 -- r 2)] h= high

b= leg length

d= waist thickness

t= average leg thickness

R= inner arc radius

r= end arc radius Calculate the weight of I-beams per m of 250 mm ×118mm ×10mm. From the metal material manual found that the I-beam t is 13, R is 10, r is 5, then weight per m = 0.00785 ×[250 ×10+2 ×13 × (118 -- 10) +0.615 × (102 -- 52)]=42.03kg

The steel plate

(kg/m2) W= 7.85 ×d d= thickness of 4mm steel plate, calculate the weight per m2. Weight per m2 =7.85 ×4=31.4kg

Steel pipe (incl. none

Sewing steel pipe and welding

Steel pipe (kg/m) W= 0.02466 ×S (D -- S) D= Outer diameter

S= seamless steel pipe with wall thickness and outer diameter of 60 mm and wall thickness of 4mm, calculate the weight per m. Weight per m = 0.02466 ×4 × (60 -- 4) =5.52kg