Carbon A366


Cold rolled commercial quality sheets are produced from rimmed, cast, capped, or semi-killed steel and are intended for exposed or unexposed parts involving bending, moderate drawing or forming and welding. They may be bent flat on themselves in any direction without cracking.Cold rolled drawing quality sheets are produced from special killed steels, and are intended for parts involving severe forming or drawing. Sheets of this quality have a greater degree of ductility and are more consistent in performance because of higher standards in production, selection, and processing of the steel. The surface finish is a dull matte texture.

American Specifications:   Commercial quality – ASTM A366; drawing quality – ASTM A620

British Specifications:   Commercial quality – 1449 4 CR, 1449 4 CS; drawing quality – 1449 1 CR, 2 CR

Applications:   Practical experience is usually sufficient to determine whether commercial quality or drawing quality is required for a given part. Where experience is not adequate, the Scribed Square Test (ASTM A568) can prove helpful. A grid of one inch squares is marked on the section representing the most severe draw. The squares are measured for percent increase in area after drawing. Experience has shown that commercial quality is usually satisfactory if the increase in area is less than 25%. If more than 25%, drawing quality is recommended.

Size Range:   28 ga – 10 ga


Typical Chemical Analysis:

Commercial Drawing
Quality Quality
C .15 max .10 max
Mn .60 max .50 max
P .030 max .020 max
S .035 max .030 max
Typical Mechanical Properties:

Commercial Drawing
Quality Quality
Tensile strength (ksi) 38-50 36-46
Yield point (ksi) 25-35 23-30
Elongation (% in 2″) 35-42 38-43
Rockwell hardness RB40-RB60 RB38-RB50

Weldability:   Yes

Size & Weight Table:

Cold Rolled Sheet
Gauge Lb/ft²
28 Ga. (.0149″) 0.625
26 Ga. (.0179″) 0.75
24 Ga. (.0239″) 1.0
22 Ga. (.0299″) 1.25
20 Ga. (.0359″) 1.50
18 Ga. (.0478″) 2.0
16 Ga. (.0598″) 2.5
14 Ga. (.0747″) 3.125
13 Ga. (.0897″) 3.75
12 Ga. (.1046″) 4.375
11 Ga. (.1196″) 5.0
10 Ga. (.1345″) 5.625