Industries
Bent Pipe for Highway Sign Structures
Cantilever and overhead sign structures, bent from large-diameter pipe to a state DOT drawing.
What dot transportation signage work brings to a bending shop
Cantilever sign arms, overhead sign bridges and gantries, luminaire and signal mast arms, and the bent uprights that carry them.
A sign gantry is a large-diameter bend with a very specific job: it has to hold a sign over live traffic for decades, in wind, without fatigue cracking at the bend. The radius is generous and the wall is heavy, which puts it squarely in induction bending territory. The photograph on this site of an overhead sign structure spanning US-75 in Tulsa, with the downtown skyline behind it, is that work.
Codes and standards: State department of transportation standard drawings, with AASHTO governing the structural design of signs, luminaires and traffic signals. Send your project specification with the enquiry and we will confirm in writing what we certify against before anything is cut.
Galvanizing and the bend
Sign structures are almost always galvanized, and galvanizing after bending is the normal sequence for a good reason: hot dip galvanizing a section that has already been formed avoids putting a bend through a coating that will crack. Tell us the sequence at enquiry stage so the surface condition leaving here is what the galvanizer needs.
State DOT standard drawings vary by state and are usually specific about radius, wall and weld detail. Send the drawing number with the enquiry.
What to send with a dot transportation signage enquiry
Five numbers describe a bend: outside diameter, wall thickness, centerline radius, bend angle and the tangent length on each end. Add the material and the quantity and the job can be priced. A drawing, a sketch or a photograph of a marked-up print all work, and the quote form takes an attachment up to 25 MB.
For sign structures, send the state and the standard drawing number. Standard drawings vary by state and are usually specific about radius, wall and weld detail. Say whether the structure is galvanized and in what sequence, because a formed section is normally galvanized after bending rather than before.
Put the documentation requirements in the enquiry rather than in a later email. Material test reports, non-destructive testing and heat treatment all cost money and time. Retrofitting a documentation package onto a bend that has already been made is slow, and sometimes it is impossible.
Materials we bend
If the grade you need is not listed, ask. This is what comes through most often, not a limit.
What we can bend for you
How we would make it
Wall thickness, radius, material and schedule decide the process. Send the drawing and we will tell you which one fits.
Heat Induction Bending
Cojafex induction bending up through 42″ O.D. and 4″ wall, in any radius, angle or plane.
Coiling
Helical, spiral wound and serpentine coils, cold, up through 10″ pipe.
Cold Bending
Rotary draw bending on fourteen machines, with mandrels and wiper shoes where the radius needs them.
Mandrel Bending
Ball mandrels and wiper shoes for tight radii and thin walls that would otherwise collapse.
Large Diameter Pipe Bending
The work most shops turn away: up to 42 inch outside diameter and 4 inch wall.
Stainless and Alloy Bending
Stainless, duplex, Hastelloy, titanium and nickel alloys, bent without wrecking the metallurgy.
Questions we get from dot transportation signage buyers
Do you bend highway sign structures?
Yes. Large-diameter pipe bent for cantilever and overhead sign structures is regular work here, including a gantry spanning US-75 in Tulsa.
Can you work to a state DOT standard drawing?
Yes. Send the drawing number and the state with the enquiry, because standard drawings vary and are usually specific about radius, wall and weld detail.
Can the structure be galvanized?
Galvanizing normally happens after bending rather than before, so a formed section is not put through a coating that will crack. Tell us the sequence at enquiry stage so the surface condition leaving here suits the galvanizer.
Have a drawing? Send it over.
Send a drawing or a sketch and our team will get back to you with a quote.