Steel Rain Gutters and Downspouts have some advantages and some disadvantages. Before Seamless Aluminum Gutters were available(pre-1980s), Steel was really the #1 material of choice when manufacturing Rain Gutters and Downspouts. Many properties in and around southern California still have the original steel gutter systems on the property.
Although Steel gutters do tend to be a bit stronger Than a seamless Aluminum Gutter (stronger as far as dent resistant) Steel Gutters like the ones pictured above are "Sectional gutters" not available in a seamless form due to the thickness of the material. These all have to be Primed, Painted, Then installed in 10-20 foot sections.
Since Steel tends to rust quite easily (Aluminum does not rust) It is imperative that the gutters are installed properly with the correct amount of slope so that there is no standing water left in the gutter system after heavy rains. Regular cleaning and maintenance is also extremely important when dealing with steel gutter products. Wet Leaves and debris left sitting in the gutters for prolonged periods of time will usually rot them out and result in corrosion and often times ugly red rust stains running down the face of your home.Another common problem is the painting requirements. Bonderized or Galvanized steel (both common types of steel used in gutter systems) will generally need a fresh coat of paint about every 5 years. Paint seems to have a hard time adhering to the metal for longer than that.
If you have your mind set on steel regardless of some of the issues which we have addressed here, Maybe using a pre-painted steel product would be a good way to go. The thinner gauges are available in a seamless form (26 or 28 gauge) and sectional gutters are available in 24 gauge .below you will find a color chart showing the colors available for the 24 gauge sectional gutters. (one advantage of the sectional steel gutters is they can be fabricated into virtually any shape or size that you desire)
Steel 24 gauge color selection for custom shaped gutters or Downspouts