[Towertalk] RE:Help locating freestanding tower

[ROBKEL@aol.com]

Troy, et al:

Regarding a free standing tower, you might check out www.heightstowers.com.
They make a very nice series of aluminum towers, complete with engineering 
specs, and a Fold-over kit that makes it easy to work on antennas at ground 
level. 

Regarding bolt selection: this is more complicated than it may appear for a 
SS tower. BTW, there are no "Grade 5 SS bolts"  There  are SS bolts per F593C 
that are good, but not as strong as Grade 5 medium carbon or Grade 8 alloy 
steel bolts. If you want to know more visit "the bolt supply house ltd" 
website. There are many other good websites that can provide similar 
engineering data.
Bolts in a SS tower are most likely in shear, which is the worse type of load 
for a bolt.  Most Bolts are rated for tensile strength in psi, and are 
derated to "allowable stress" by taking the allowable to be 60% of the rated 
maximum.
Shear stress is lower still, 1/3 of the allowable tensile stress. 
These are the design values that a PE would use to design a tower according 
to current accepted standards. 

Regards,
Bob, W5LT