Finishes and Specs
Every size comes in hot rolled, pickled and oiled, or galvanized steel, made to the specification your drawing calls for.
Three Steels, Chosen for Where the Tube Goes.
The finish comes from the coil we start with, so it is set before the tube is formed.
Hot Rolled
Mill scale left on. The lowest-cost tube, for parts that get painted or powder coated after fabrication.
A500, A513 Type 1aPickled and Oiled
Scale removed in acid, then oiled. Cleaner welds and better paint adhesion, with no scale to flake off.
A500, A513 Type 1bGalvanized
Made from zinc-coated coil, G90 to G235, with a clear coat over the zinc as standard, for tube that lives outdoors: solar racking, fence, trailers and farm equipment.
A787, A500Galvanized Tube or Galvanized After Fabrication.
There are two ways to get a zinc-coated tube part, and they suit different jobs.
Tube From Coated Coil
The tube is formed from steel that was galvanized as coil, the weld seam is coated again in line, and a clear coat goes over the outside as standard, or a conductive clear coat for solar racking. The coating is thin and even, the tube is clean to handle, and there is no second trip to a galvanizer. Clear Coat
Hot-Dip After Fabrication
The finished part is dipped in molten zinc, which coats the welds, cut ends and inside faces with a much heavier layer. It costs more and adds a step, and is chosen for parts that sit in soil, water or heavy road salt.
Which to Choose
Fence, racking, trailers and farm equipment are usually built from galvanized tube and touched up at the welds. If your drawing calls for hot-dip galvanizing after fabrication, order bare tube instead, since galvanized tube usually has to be stripped before it can be dipped.
Welding and Painting Each Finish.
The finish decides how much cleaning a part needs before it is welded and coated. Pick it for the last step in your shop, not the first.
Hot Rolled
Mill scale is hard and dark, and paint sticks to the scale rather than the steel. For a lasting coat, grind the weld areas and blast the part before painting or powder coating. Where the part is hidden or only primed, hot rolled is the economical choice.
Pickled and Oiled
With no scale, welds run cleaner and coatings bond to bare steel. The oil keeps the surface from rusting in storage and has to be washed off before painting, powder coating or plating, usually in a parts washer or a pretreatment line.
Galvanized
Welding burns the zinc off near the joint and gives off zinc fumes, so weld with good ventilation and follow your shop's safety rules. Touch up the weld area with a zinc-rich paint to restore protection where the coating is gone.
Questions.
Not sure which finish suits the part? Tell us how it will be welded, painted or exposed, and sales will suggest one.
What is the difference between hot rolled and pickled and oiled tube?
Hot rolled tube is made from steel with its mill scale left on. Pickled and oiled steel has the scale removed in acid and a light oil applied, so it welds, paints and plates more cleanly.
How is the weld protected on galvanized tube?
Galvanized tube is made from zinc-coated coil. The weld seam is coated again in line, right after welding. A clear or conductive clear coat can then go over the whole outside.
What is clear-coated galvanized tube?
Galvanized tube with a thin clear coat over the zinc, cured by ultraviolet light on the mill. It helps protect the zinc in storage and stays flexible for bending. Every galvanized size can be ordered with clear or conductive clear coat; Clear Coat has the test results.
Will hot rolled or pickled tube rust?
A light surface rust is normal on bare steel and isn't a defect. Keep tube dry and covered; our claims policy allows 7 days for rust claims on hot rolled and 30 days on pickled and oiled.
What is white rust on galvanized tube?
A white, powdery zinc oxide that forms when galvanized tube is stored wet and tightly stacked. Our clear coat over the zinc helps against it, but store bundles dry and ventilated; white rust claims must be made within 60 days of shipment.
Can you weld galvanized tube?
Yes. Welding burns the zinc off near the joint and gives off zinc fumes, so weld with good ventilation, then touch up the weld with a zinc-rich paint.
Do I need to clean pickled and oiled tube before painting?
Yes. The oil protects the steel in storage but stops paint and powder from bonding, so wash it off first. Once clean, pickled steel has no scale under the coating.
Which finish is best for powder coating?
Pickled and oiled, once the oil is washed off, since there is no scale to lift the coating. Hot rolled tube can be powder coated too, but it should be blasted first.
Is galvanized tube the same as hot-dip galvanized?
No. Galvanized tube is made from zinc-coated coil, with the weld seam coated again in line. Hot-dip galvanizing coats a finished part after fabrication, with a heavier layer that also covers welds and cut ends.
What do I need to send for a quote?
The size and wall, the spec and finish, the length (mill length, or your cut length and tolerance), the quantity per order or per year, and where it ships. The quote form asks for each one. Name the spec and the finish together; the technical data below shows which go together. If you aren't sure, say how the part will be welded, coated and used.
Technical Data.
Which specification comes in which finish.
Which Spec Comes in Which Finish.
Order by specification when the tube carries a load or a drawing names one; order by finish when the surface matters most.
| Specification | Hot rolled | Pickled and oiled | Galvanized |
|---|---|---|---|
| A500 structural | Yes | Yes | Yes |
| A513 mechanical | Type 1a | Type 1b | – |
| A787 galvanized mechanical | – | – | Yes |
Tell Us the Size,
Wall and Footage.
One size or a whole program, in mill lengths or cut to your length. The quote form takes about two minutes.