In Robot, the convention of designating sections composed of 2 angles is based on the following databases:
AMERICAN SECTION DATABASE AISCPRO.XML
Sections:
DL - 2 equal-leg angles
DLL - 2 angles with longer legs touching
DLS - 2 angles with shorter legs touching
Each section name (in addition to the symbol DL, DLL, DLS) is made up of 3 parts. They will be described using the DLL 2.5x2x10.1875 section as an example. The numbers indicate:
2.5 - DIM1 (first characteristic section dimension)
2 - DIM2 (second characteristic section dimension)
10.1875 - the third number is made up of 2 parts; 3 numbers may appear before the dot:
0 - means that the angles are touching
10 - means that the spacing of the angles is equal to 3/8 of an inch
20 - means that the spacing of the angles is equal to 3/4 of an inch;
The number located after the dot indicates the thickness of the angle in fractions of an inch (for example, 0.1875 is equal to 3/16 of an inch).
CANADIAN SECTION DATABSE CISCPRO.XML
Sections:
LLEA - 2 equal-leg angles touching
LLEB - 2 equal-leg angles spaced 8 mm apart
LLEC - 2 equal-leg angles spaced 10 mm apart
LLED - 2 equal-leg angles spaced 12 mm apart
LLEE - 2 equal-leg angles spaced 16 mm apart
LLEF - 2 equal-leg angles spaced 20 mm apart
LLLA - 2 angles with longer legs touching
LLLB - 2 angles with longer legs spaced 8 mm apart
LLLC - 2 angles with longer legs spaced 10 mm apart
LLLD - 2 angles with longer legs spaced 12 mm apart
LLLE - 2 angles with longer legs spaced 16 mm apart
LLLF - 2 angles with longer legs spaced 20 mm apart
LLSA - 2 angles with shorter legs touching
LLSB - 2 angles with shorter legs spaced 8 mm apart
LLSC - 2 angles with shorter legs spaced 10 mm apart
LLSD - 2 angles with shorter legs spaced 12 mm apart
LLSE - 2 angles with shorter legs spaced 16 mm apart
LLSF - 2 angles with shorter legs spaced 20 mm apart
Each section name (except for the letter symbol) is made up of 3 parts. They will be described using the LLLB 51x38x4.8 section as an example. The numbers indicate:
51 - DIM1 (first characteristic section dimension)
38 - DIM2 (second characteristic section dimension)
4.8 - the third number indicates the angle thickness in mm.
BRITISH SECTION DATABASE UKSTPRO.XML
Sections:
CUAL - 2 angles with longer legs touching
CUAS - 2 angles with shorter legs touching
Each section name (except for the CUAL, CUAS symbol) is made up of 3 parts. They will be described using the CUAL 60x30x1206 section as an example. The numbers indicate:
60 - DIM1 (first characteristic section dimension)
30 - DIM2 (second characteristic section dimension)
1206 - the third number is made up of 2 parts:
the first number (12) indicates the spacing between the angles (in mm)
the second (06) indicates the angle thickness (in mm).
If the thickness is less than 10 mm, then the numbers are divided by the zero digit. For example, if the third number is 807.9, this means that the thickness of the angle is 7.9 mm.