[TowerTalk] Help identifying alloy in mast

[al.n6ta at gmail.com]

Is it sufficient to ask for 4130 or 1026 or must one consider the details of the heat treat, quench and temper, etc.  If you go to a supplier, you will pay for the 'certs' that guarantee that you get what you pay for.
I do not know but bought the certs after talking to the tubing yard 'experts'.
Al
N6TA

-----Original Message-----
From: john at kk9a.com <john at kk9a.com> 
Sent: Monday, February 10, 2020 11:30 AM
To: Richard (Rick) Karlquist <richard at karlquist.com>
Cc: towertalk at contesting.com
Subject: Re: [TowerTalk] Help identifying alloy in mast

The first question is do you really need a 4130 mast or is 1026 sufficient.  1026 is pretty strong and if you need a stronger mast using 2"
diameter is probably not the best choice.  I have no idea why this became the standard, but I have not used a 2" mast in decades. My 80 ft tower has a homebrew 3" diameter 1026 DOM mast which if I recall correctly is stronger and was definitely less money than Ø 2" 4130 plus it is easier to clamp to and also climb. At my Aruba station I used Ø 2 1/2 6061 for my 4el monobanders which held up fine in that tropical environment.  I really miss WD9P's online mast calculator, it made it easy to see how different materials and different diameters and wall thicknesses affected mast strength and what is needed for a given windload.

73,
John KK9A

Sent via the Samsung Galaxy 7 edge, an AT&T 4G LTE smartphone.


On Mon, Feb 10, 2020 at 12:46 PM Richard (Rick) Karlquist < richard at karlquist.com> wrote:

>
>
> On 2/10/2020 7:35 AM, john at kk9a.com wrote:
> > There are companies that purchase scrap metal from manufacturing plants.
> > They have an analysis gun that can show the chemical composition of 
> > carbon steel. I have watched someone use one, they are very quick 
> > and appear to be accurate however you would need to remove the zinc 
> > in the test area.  Another option is to cut off a sample and test 
> > the hardness using a Brinell Hardness testing machine and compare it 
> > to the chrome molly and 1026 steel specs.
> >
> > For some reason hams seem to be obsessed with 2" chrome molly masts.
> >
> > 73,
> >
> > John KK9A
> >
>
> It's good to know that it can be tested.  It would probably require 
> "connections" to get this done at a price that wouldn't exceed the 
> value of the mast.
>
> Can you expand on your comment about the chromoly obsession?
> I too keep reading the chromoly "hype" (?) here on TT.
> Is it possibly overrated? Or maybe it's the real deal.
> I don't have an opinion as a non-expert; just trying to learn about it.
>
> Rick N6RK
>