Here’s a quick fact: Flat isn’t always just flat. More specifically, when it comes to stainless steel bars, there are two different types of flat: true flat and edge-conditioned flat (also known to some as gauered flat).

For a high-level comparison, one is produced to specifications straight from the mill as a bar (true flat) and the other is produced from other types, like plate (edge-conditioned flat). But let’s dig a bit deeper about why and when to consider each type. 

True Flat Stainless Steel Bars

True flat stainless steel bars are those that have been produced on a rolling mill. In instances when the material needs to be polished in order to create a more consistent finish across all four sides (think architectural and aerospace applications), true flat bars often win out. 

Other typical end uses for true flat stainless steel bars include food machinery, conveyor equipment, packaging equipment, bottling equipment, separators, and chemical processing, among others.

When compared to edge-conditioned flat stainless steel bars, true flat has a wider variety of grades:

304/304L stainless steel flat bar
316/316L stainless steel flat bar
303 stainless steel flat bar
• 17-4 stainless steel flat bar

Why use true flat stainless steel bar: 

• Tighter tolerances – thickness & width
• Better squareness on edge
• Can be produced as hot roll annealed and pickled or cold drawn

Be aware:

• Longer mill lead-times
• Cost of production can be higher than cut flats
• A limited number of US-based mills produce true flat bars 

Edge-Conditioned Flat Stainless Steel Bars

Edge-conditioned flat stainless steel bars don’t start out as bars. They have been slit from coil or sheared or saw cut from plate, before the edge is conditioned. This means the edges may have a slightly different finish from the flat sides. In addition, edge-conditioned flat stainless steel bars may not be truly as flat as a true flat stainless steel bar. 

Among the common uses for edge-conditioned stainless steel bars are stiffeners for tank manufacturing, ornamental applications, grab bars, bar rings, and structural members, among others. 
Typical grades for edge-conditioned stainless steel flat bars are 304/304L stainless steel flat bar and 316/316L stainless steel flat bar.

Why use edge-conditioned stainless steel flat bar:

• The cost of product is typically less than true flat
• There is a larger market for cut flats
• Can be an outstanding value where tolerances will permit
• Widely available and can typically have short lead times
• Can be purchased already polished on two or four sides

Be aware:

• Tolerances are typically not as tight, as it is difficult to use precision equipment
• Edges are not as square – difficult to machine or finish easily
• Thickness limitations exist due to slitting, shearing and gauge-edge constraints

Ready to find the right stainless steel flat bar for your project?