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Tubing explained (DOM HREW CREW ERW)

Discussion in 'Bay Area Metal Fabrication' started by JLee, Nov 3, 2011.

  1. Nov 3, 2011 at 12:29 PM

    JLee [OP] The Man! Vendor

    Jul 20, 2010
    First Name:
    Bay Area NorCal
    02 Extra cab SAS Linked front and rear
    I lost track thousands of dollars ago.
    There is so much miss conception on steel tubing so I did some searching for info and numbers and this is what I found.

    Here is some valuable information dealing with types of Tubing, including structures, specifications, applications, size ranges, and chemical analysis.

    *Credit goes to 'Old Scout' on Utah's Rock Crawling and Off-Road Forum , thanks for the info.*


    DOM, ERW, HREW...all types of "mechanical tubing", as opposed to pipe. All mechanical tubing is dimensioned by OD and a wall thickness.

    DOM is actually not a type of tubing, but a process that is applied to tubing after it is initially constructed. It is Drawn Over a Mandrel...which "cold works" it, giving more exact dimensions, smoother finish, and better alignment of the crystal latice structure. It is Not seamless tubing, and it started life as some sort of EW (electric welded) tubing. Most commonly, when people say "DOM" they mean 1020 mild carbon steel rolled electric welded tubing that is then drawn over a mandrel.

    Other mechanical tubing that is not necessarily drawn over a mandrel can be either hot or cold rolled (i.e. rolled from a flat strip into a tube when either hot or cold) and most commonly available will then be electric resistance welded to form the final tube.

    Generally...cold forming and cold working add strength and uniformity to a product, and reduce stress.


    So VERY BASICALLY, in terms of strength you usually have, in order:

    CREW (cold rolled electric welded)
    HREW (Hot....)

    Again...these are all just processes, to fully call out the material, you need to specify the type of steel...but most commonly we are talking about either 1020 mild carbon steel, or 4130 or 4140 Chromium molybdenum alloy steel or 4340 nickel chromium molybdenum alloy steel.

    Structural tubing that offers high strength-to-weight ratio and a higher impact toughness. The steel is fully killed and melted to fine grain practice. Customers may specify yield, tensile, elongation and charpy impact values according to their needs. This product is to minimize the probability of catastrophic failure of vehicle cab structures in the event of a roll-over accident.
    American Specifications: ASTM A500 for dimensional tolerance, squareness, straightness, twist and corner radii. Mechanical properties can vary by end user.

    Applications: Cabs for agricultural vehicles, road and off-road construction equipment, and lift trucks.

    Size Range: 2" - 12" (50 mm - 305 mm) sq and the standard rectangle sections of the same perimeters. Rounds available as special inquiries.

    Typical Chemical Analysis: Alloying elements may be added to achieve mechanical property requirements.
    C .22 max
    P .04 max
    Mn 1.65 max
    S .05 max
    Typical Mechanical Properties: Can vary to customer specification
    Tensile strength (ksi) 70 min
    Yield point (ksi) 50 min
    Elongation (% in 2") 20 min
    Charpy impact Wall Ft/lb (min) Temp (°F)
    3/16" 11.0 -20
    1/4" 13.0 -20
    3/8" 18.0 -20

    Machinability: Good

    Weldability: Excellent

    Testing: Generally one tensile test and one set of three impact tests are taken from each lot of tubing. Tubing is tested in accordance with the latest revision of ASTM A370. Certification of material is available.

    Materials Resource Page Number: 41



    1020 is normally used in the manufacturing of small-diameter or thin-wall DOM steel tube. DOM is formed from strip and electric-resistance welded, then cold drawn to size. The cold drawing process causes the weld line to virtually disappear.
    American Specifications: ASTM A513 Type 5

    British Specifications: 040 A 20, 070 M 20

    Applications: Mechanical, hydraulic cylinders, shaft, tight tolerance requirements

    Size Range: 1/4" - 14&1/2" (6 mm - 368 mm) OD; .035" - .625" (.9 mm - 16 mm) wall

    Typical Chemical Analysis: C .15-.25
    Mn .30-.60
    P .040 max
    S .050 max

    Typical Mechanical Properties: Tensile strength (ksi) 80
    Yield point (ksi) 70
    Elongation (% in 2") 15
    Rockwell hardness RB80


    1018 is normally used in the manufacturing of cold drawn and hot finished seamless tube. The production of seamless tube is generally made by piercing a hot rolled bar. Hot finished is generally furnished in the unannealed condition, whereas cold drawn seamless is supplied in the unannealed or S/R annealed conditions, depending on the size.
    American Specifications: ASTM A519

    British Specifications: 070 M 20, 080 A 15

    Applications: Axles, shafts, gears, bearings

    Size Range: 1/8" - 24" (3 mm - 610 mm) OD; .0218" - 3.00" (.6 mm - 76 mm) wall

    Typical Chemical Analysis: C .15-.20
    Mn .60-.90
    P .040 max
    S .050 max
    Typical Mechanical Properties: CDS HFS
    Tensile strength (ksi) 80 60
    Yield point (ksi) 60 35
    Elongation (% in 2") 15 30
    Rockwell hardness RB88 RB60




    1010 is normally used in the manufacturing of electric-resistance welded tube. The product is available normally in cold rolled strip (16 gauge and lighter), and hot rolled strip (.083" wall and heavier). The product can be obtained in the as-welded condition (flash-in) or in the flash-controlled condition.

    American Specifications: ASTM A513 Type 1 and Type 2

    British Specifications: 040 A 10, 045 A 10

    Applications: Machinery stands, exhaust tubes, handles, hand rails, display stands, conveyor rollers

    Size Range: 1/4" - 10" (6 mm - 254 mm) OD; .028" - .375" (.7 mm - 10 mm) wall

    Typical Chemical Analysis: C .08-.13
    Mn .30-.60
    P .035 max
    S .035 max
    Typical Mechanical Properties: Tensile strength (ksi) 45
    Yield point (ksi) 32
    Elongation (% in 2") 15 min
    Rockwell hardness RB55 min


    1026 STEEL TUBE


    1026 grade is normally used in the manufacturing of DOM, cold drawn seamless and hot finished seamless. This grade normally furnished over 2" OD, with walls heavier than .156". A variety of thermal treatments can be supplied, depending on the type and size of material.

    American Specifications: ASTM A519 (SMLS), ASTM A513 Type 5 (DOM)

    British Specifications: 070 M 26

    Applications: Mechanical, hydraulic cylinders, shaft, tight tolerance requirements

    Size Range: 1/8" - 24" (3 mm - 610 mm) OD; .028" - 3.00" (.7 mm - 76 mm) wall

    Typical Chemical Analysis: C .22-.28
    Mn .60-.90
    P .040 max
    S .050 max
    Typical Mechanical Properties: CDS DOM HFS
    Tensile strength (ksi) 87 80 70
    Yield point (ksi) 72 70 47
    Elongation (% in 2") 10 10 28
    Rockwell hardness RB89 RB85 RB78


    A few more facts:

    CREW = Cold Rolled Electric Welded
    HREW = Hot Rolled Electric Welded
    ERW = Electric Resistance Welded
    CDS = Cold Drawn Seamless
    DOM = Drawn Over Mandrel
    HFS = Hot Finished Seamless
    CDBW = Cold Drawn Butt Welded (Continuous)
    W&D = Welded and Drawn

    11 GA = .120 12 GA = .105 13 GA = .090 14 GA = .075
    16 GA = .060 18 GA = .048 20 GA = .035

    1-3/4" x .095 wall is 1.59 lbs/ft
    1-3/4" x .120 wall is 2.09 lbs/ft
    Steel = .2843 lb/cu in Aluminum = .0975 lb/cu in
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