Listed below are the Original Isomat Boom Sections.
Original Isomat Booms are easily identifiable by their angularity (they are essentially
Octagonal, and hard chined), and an integral internal flat track on the bottom for special
Boom Bails. Later Booms Sections used by Isomat had smooth sides and
an integral internal flat track on the bottom, See:
Sparcraft FB Booms. For replacement
Boom Parts, determine which Boom Section you have by measuring maximum Outside Dimensions.
Click on individual Boom Sections, below, to see hardware commonly used with those Sections.
Note that some Booms have been produced with the Isomat AutoReef (single line)
Reefing System, using specially modified Boom End castings and additional components.
For details, See: Isomat AutoReef System.
See also
Isomat Masts & Components, and
Isomat Spreaders & Components.
And Isovang Solid Vangs & Components.
Isomat Boom Sections 
CrossSection
(typical) 
Section # 
Maximum Outside Dimensions
(Height x Width) 
Wall Thickness 
Weight (lbs./ft) 
Moments of Inertia
Ixx Iyy
(in4) (in4) 

NB16 
2 7/8" x 3 1/2" (72 x 90mm) 
.070" 
1.08 
1.11 
1.06 
NB26 
4" x 3 1/2" (100 x 90mm) 
.098" 
1.76 
2.48 
2.07 






NB32 
5" x 4
3/8" (128 x 110mm) 
.098" 
2.16 
7.04 
3.96 
NB40 
5 7/8" x 4
3/8" (150 x 110mm) 
.112" 
2.71 
11.22 
4.97 
NB55 
7" x 5
1/8" (180 x 130mm) 
.114" 
3.72 
20.42 
6.97 
NB70 
10 1/4" x 4
1/4" (260 x 109mm) 
.138" 
5.16 
65.09 
12.88 
