ok guys. I am building a 4 link and using DOM. I have a question about the metal properties of DOM. I know it is better than ERW and HREW and pipe (at least to some it is in regards to pipe and I don't want to get that debate started)..My question is regarding the "strength" of DOM.What makes a piece of DOM stronger than a piece of solid cold rolled steel given the o.d. being equal? what type of metal (or maybe grade is a better term) is DOM(cold rolled and hot rolled are examples of types of metals and 1018 or 1020 being examples of grades)?Certainly the DOM is lighter than the solid ;but, why exactly is it stronger? I know I could search ;but, searching DOM or tubing is about as fun as searching supsension or link and having to read through that "god of ..... " thread which I fear if I say it will come back around :D Thanx in advance

I am defininitely not a Guru, but I will try my best to answer your questions.

I will dodge the pipe/DOM fight as well, even though I understand the differerences, and have my opinion to what is the best material to use.

DOM is not stronger than cold rolled solid steel of the same diameter. Not nearly as strong, but BUT becuase you can have a larger OD of tubing that has the same weight as a smaller OD solid, it has a higher yeild strength(bending resistance) than solid steel for it's weight. Repeating to make sure that I was clear. Tubing resists bending better than solid for a given weight. If weight is of no concern to you, then solid links are better, because they will be much stronger(given the same or nearly the same OD as you mentioned in your post), and also completely removes the possibility of denting your links.


1018 and 1020 are both common grades of steel that are used to make DOM tubing. DOM tubing is cold rolled.

Sean

Thanx station. ..which has a stronger yield the 1018 or the 1020? i don't think the solid bar route is very efficent considering weight. IMO 2 O.D. solid links at 49 inches long would be a tad heavy:eek: Just curious about one more thing. One supplier that I talked to had DOM listed seperate from "seamless"..Or better put had a price and listing for DOM and another price and listing for "seamless"..what is the difference?I always thought they were one in the same.

I will pipe in with my limited knowledge. I know that "seamless" is different than DOM because DOM is basically HREW with the interior welded seam smoothed over by "drawing over a mandrel". There is still a seam, it is just compressed. I do not know how they make "seamless", but to me it seems like it should be a piece of solid with the interior machined out, no?

BTW, please clarify, but I was under the impression that DOM "is" stronger than HREW because it is "cold worked" which makes it stronger. Am I correct?

Originally posted by zachv
[B I do not know how they make "seamless", but to me it seems like it should be a piece of solid with the interior machined out, no?

[/B]

They take a solid rod and piercing it with a hot spear. It's called 1018 seamless.

Specs for my supplyer:

1020 DOM STEEL TUBE
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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

Size & Weight Table:
Round Carbon Steel Tube


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




Machinability: Excellent

Average Cutting Speed: 120 ft/min

Weldability: Excellent

Carburizing: May be carburized

Corrosion Resistance: Poor

Materials Resource Page Number: 28
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1018 COLD DRAWN AND HOT FINISHED SEAMLESS TUBE


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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

Size & Weight Table:
Round Carbon Steel Tube


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




Machinability: Good

Average Cutting Speed: 130 ft/min

Weldability: Excellent

Carburizing: May be carburized

Corrosion Resistance: Poor
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1010 ELECTRIC WELD STEEL TUBE


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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

Size & Weight Table:
Round Carbon Steel Tube


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




Machinability: Good

Average Cutting Speed: 110 ft/min

Weldability: Excellent

Corrosion Resistance: Poor

Originally posted by onetonwillysands10
Thanx station. ..which has a stronger yield the 1018 or the 1020? i don't think the solid bar route is very efficent considering weight. IMO 2 O.D. solid links at 49 inches long would be a tad heavy:eek: Just curious about one more thing. One supplier that I talked to had DOM listed seperate from "seamless"..Or better put had a price and listing for DOM and another price and listing for "seamless"..what is the difference?I always thought they were one in the same.

The material data information that Old Scout posted will answer some questions.

One thing that I may be wrong about is that 1018 is often Drawn Over Mandrel as well. It is different in 1020 DOM in that it starts out as a solid rod which is peirced, where 102 starts out as a strip od steel which is bent into a tube, and welded down it's length. Both can be drawn over mandrel, and be sold as DOM tubing.

Old Scout is right about the seamless tubing. It starts out as a peice of solid, and the center is peirced through.

It is important to ask your supplier about the material that you are getting. There can be a lot of variations of 1018. There is allot about the material that is not described by those numbers. Your supplier should be able to supply you with a material data sheet.

For instance notice how all of the specs of the 1018 have two different numbers. This has to do with the differences between the cold drawn, or hot finished process. If the tubing was The tubing was Drawn over Mandrel, the numbers would change again.

Just wondering OneTon...... How much does your supplier want for their tubing(both DOM, and seamless)?

Sean