Project Description

Structural Tubing

Structural tubing per ASTM A500 is tubing produced and used for structural applications. Standard strength requirements of the tube help dictate applications for which certain tubing is most appropriate. Structural tube is often referred to as hollow structural sections or HSS. Structural Tubing, especially rectangular sections, are commonly used in welded steel frames where members experience loading in multiple directions. Square and circular HSS are very efficient shapes for this multiple-axis loading as they have uniform geometry along two or more cross-sectional axes, and thus uniform strength characteristics. This makes them good choices for columns. They also have excellent resistance to torsion. The flat square surfaces of HSS structural tubing can ease construction, and they are sometimes preferred for architectural aesthetics in exposed structures. HSS structural tubing is most commonly produced to ASTM A500 grade B standards, but can also be available in ASTM A1085 as well. Structural products are ordered to a specific outside dimension (OD) and gauge or wall thickness.

 

Stocked Size Range And Shapes

  1. Square: 0.500″ to 16.000″ with 0.065″ to 0.625″ Wall Thickness
  2. Rectangle: 1.000″ x 0.500″ to 20.000″ x 12.000″ with 0.065″ to 0.625″ Wall Thickness
  3. Round: 0.750″ to 20.000″ O.D. with 0.065″ to 0.625″ Wall Thickness

 

Manufacturing Process

ASTM A500 structural tubing is welded tubing made from flat-rolled steel, formed through a roller system and welded using electric-resistance welding. Longitudinal butt joints of welded tubing shall be welded across its thickness in such a manner as to assure the structural design strength of the tubing section. Welded structural steel tubing is normally furnished without the removal of inside flash.

 

Benefits Of Structural Tubing

  1. Strength
  2. Appearance
  3. Uniformity
  4. Ease Of Fabrication
  5. Cost Effectiveness
  6. Resistance

 

Applications By Industry

  • Construction & Heavy Equipment
  • Agriculture
  • Infrastructure
  • Fluid Handling
  • Machinery
  • General Fabrication And Machining
  • Automotive & Transportation

 

Chemical Requirements

A500 Grades A, B and D Grace C
Heat Analysis Product Analysis Heat Analysis Product Analysis
Carbon, max 0.26 0.3 0.23 0.27
Manganese, max 1.35 1.4
Phosphorus, max 0.035 0.045 0.035 0.045
Sulfur, max 0.035 0.045 0.035 0.045
Copper, when copper steel is specified, min 0.2 0.18 0.2 0.18

 

EN10210/10219 C Max. Si Max. Mn Max. P Max. S Max N Max.
S235JRH 0.17 1.40 0.040 0.040 0.01
S275J0H 0.20 1.50 0.035 0.035 0.01
S275J2H 0.20 1.50 0.030 0.030
S355J0H 0.22 0.55 1.60 0.035 0.035 0.01
S355J2H 0.22 0.55 1.60 0.030 0.030
S355K2H 0.22 0.55 1.60 0.030 0.030

 

Mechanical Properties

Tensile strength refers to the amount of stretching stress a material can withstand before breaking or failing. The ultimate tensile strength of A500 carbon steel is calculated by dividing the area of the steel by the stress placed on it, which is expressed in terms of pounds or tons per square inch of material. Tensile strength is an important measure of A500’s ability to perform in an application. A500 carbon steel’s tensile strength is described in the chart below.

A500 Grade A Grade B Grade C Grade D
Tensile strength, mn, ps (MPa) 45 000 (310) 58 000 (400) 62 00 (427) 58 000 (400)
Yield strength, mn, psi (MPa) 39 000 (269) 46 000 (317) 50 000 (345) 36 000 (250)
Elongation in 2 in. (50.8 mm), min, %A 25B 23C 21D 23C

 

Mechanical Properties Elongation (%) Impact Energy (KV J)
Steel Grade Yield Strength (Mpa) Tensile Strength (Mpa) At Test Temperature of °C
-20 0 20
S235JRH 235 360-510 26 27
S275J0H 275 410-560 23 27
S275J2H 275 410-560 23 27
S355J0H 355 510-680 22 27
S355J2H 355 510-680 22 27
S355K2H 355 510-680 22 40

 

Permissible Dimensional Variations for Outside Dimensions

Outside diameter measurements for steel tube must be made at positions at least 2″ (50.8mm) from either end of the tubing.

Square structural tubing and rectangular structural tubing must be measured across the flats and include an allowance for convexity or concavity. Specified dimensions shall not exceed the plus/minus allowances shown in the table below.

 

Outside Dimensional Tolerances for Square & Rectangular Steel tubing

There are multiple considerations that must be accounted for when determining the outside dimensional tolerances for square and rectangular steel tubing. The chart below and the following attributes describes the exact outside dimensional tolerances for A500 carbon steel.

 

WALL THICKNESS

Minimum wall thickness at any point of measurement shall not be less than 90% of specified nominal wall thickness. Maximum wall thickness, excluding weld seams, shall not be more than 110% of specified nominal wall thickness. Wall thickness of square structural tubing and rectangular structural tubing must be measured at the center of the flat.

 

STRAIGHTNESS

Permissible variation in straightness for structural tubing is 1/8″ times the total length in feet (or 10.4mm times the number of meters) divided by five.

 

SIDE SQUARENESS

For square structural tubing and rectangular structural tubing, adjacent sides may deviate from 90° by no more than ±2°.

 

CORNER RADII

For square structural tubing and rectangular structural tubing, the radius of anyone outside corner may not exceed three times (3x) the specified wall thickness.

 

TWIST

For square structural tubing and rectangular structural tubing, the tolerances for twist (variation with respect to axial alignment) are shown in the table below.

 

Twist Tolerances for Square & Rectangular Structural Tubing

Twist is measured by either holding down one end of a square/rectangular tube on a flat surface, with the bottom side of the tube parallel to the surface plate of the two corners at the opposite end of the bottom side of the tube; or, by measuring this difference on the heavier sections by a suitable measuring device. Difference in the height of the corners must not exceed the values in the table above.

 

Contact Fushun for Steel Structural Tubing Today

Contact us for more information regarding ASTM A500 / EN 10210 / EN10219 steel structural tubing specifications and product options, or request a quote for further pricing details today.