[TowerTalk] Chrome Moly mast coating

[Jim Lux]

On 5/19/11 7:03 AM, K7LXC at aol.com wrote:

>
>      BTW it's been my experience that most people  who mention chromoly
> masts don't really need them. Many times something a lot  less expensive will
> suffice; e.g. SAE 1026 (65k psi), A530 (about the same).  What is your local
> windspeed rating and what are you proposing for antennas on  the mast? I just
> hate to see you spend money that you don't have to - them  suckers are
> expensive.

Also consider the actual failure mode: the mast bends.  It's not like 
the antennas will come crashing down on someone's head.

Unless you have an application where it has to work 24/7 because 
people's lives hang in the balance, it seems that not worrying about the 
2-3% 2 sigma wind event case might be a better overall system plan. 
Spend the money and labor somewhere else.

Save the high strength steel for things like helicopter rotor masts, 
turbine blades, bridge support cables, race car roll cages and the like: 
where failure really is catastrophic, or where strength/weight ratios 
are critical.

(I'm waiting for the first person to ask about titanium masts.  Come on, 
guys and gals, if you have to have the very best, why not?  Good 
corrosion resistance, great strength to weight ratio, etc.  Or, some 
exotic Beryllium alloy.)