[TowerTalk] [Bulk] Re: Rohn towers

Tue May 12 18:09:50 EDT 2015

Try local suppliers for grade A513 DOM tube.  A513 is the process - 
welded and then drawn over mandrel = DOM.

Onlinemetals.com sells 8' of 0.25" wall (probably overkill for 8') A513 
1020-1026 alloy for $120, and likely will supply longer if you are 
willing to pay the freight.  They have it in 8 wall thickness from 0.065 
to 0.50", so whatever strength you need, they have.  Use one of the mast 
calculators to find the wall thickness needed for 72ksi steel (their 
spec).   A513 alloy 1020-1026 has a yield of 72ksi, so likely twice or 
more whatever ungraded/unknown alloy IPS would be for the same 
wall/diameter.  A513 is not galvanized, so a good paint job is needed in 
and out.  Or take it to a hot dip galvanizer, $100 minimum here or 
$0.55/lb of steel going into the vat.

DXE says "4130 A513" which is one of about 25 steels A513 can be made 
from.  However, other suppliers say the 4130 yield is 80ksi, the ASTM 
spec is 80ksi and the "100ksi yield, 110ksi tensile" is the DXE spec.  
Other specs I found for 4130 normalized range from  64ksi to 90ksi yield.

I never figured out what hot dip galvanizing does to normalized steel 
(1500deg), but I doubt it raises the yield point.

http://www.industrialmetalsales.com/addtocart.sc?productId=1199&quantity=1 
shows 6' x 0.25" wall A513 for $46, an even better deal if they will 
ship 8'.  Not clear what steel alloy. Ask.

here is a chart with some A513 choices 
http://www.amcastle.com/Download/tubingqg240b.pdf  Armed with alloy 
data, you will likely have a more productive discussion with suppliers.

and for bedtime reading the ASTM A513 spec 
http://www.industrialtube.com/client/images/A513.pdf  I note that the 
OLM claimed yield numbers are higher than those in this spec for A513 
1020-1026 as well.

Increasing the diameter of a mast pays back much better than increasing 
the wall thickness.  So thicker than 0.25" wall is pretty much a waste 
of dollars vs going to a larger diameter.

Grant KZ1W

On 5/12/2015 14:07 PM, Patrick Greenlee wrote:
> I am searching for a less expensive source of tubing than DXE and 
> UST.   I found that US Tower sells CM tubing in 2 inch OD with walls 
> that are .25 inches thick and .375 thick.  The 1/4 wall is $379.95 
> plus freight and the 3/8 wall is (brace yourself) $1699.95 plus 
> shipping.  You order through and pay HRO, UST ships it to you.
>
> I found an on-line retailer who sells by the foot from 1 to 8 ft with 
> 8 ft priced more than 22 ft from HRO or DXE.  Still looking. If I end 
> up buying 22 ft I will probably use less than half and would likely be 
> looking to sell my surplus.
>
> I agree with Bry, there has to be a source of intermediate lengths at 
> more reasonable prices.  But where?
>
> Patrick     NJ5G
>
> On 5/12/2015 3:12 PM, Bry Carling AF4K wrote:
>> I have found a local surplus source for tubing that is well below the 
>> high retail prices at
>> ALRO. These probably exist all over the  country too...
>>
>> Bry AF4K
>>
>> On 11 May 2015 at 11:58, Scott Johns wrote:
>>
>>> One thing I have run in to with Arlo, which may be reflected in their
>>> lower pricing, is Foreign alloy.  Some of the foreign alloy has been
>>> different enough in sizing that the 0.58 sections will not telescope. I
>>> have not run into that problem with US alloy.
>>>
>>> 73, Scott W3TX
>>>
>>> On 5/11/15 11:51 AM, "Jon Pearl - W4ABC" <jonpearl at tampabay.rr.com> 
>>> wrote:
>>>
>>>> Hi Roger,
>>>>
>>>>
>>>>
>>>> I've found them very easy to work with when purchasing DOM tubing as
>>>> well as aluminum plate.  They'll even cut plate to dimensions for a 
>>>> few
>>>> bucks per cut.
>>>>
>>>>
>>>>
>>>>
>>>>
>>>> 73,
>>>>
>>>>
>>>> Jon Pearl - W4ABC
>>>> www.w4abc.com
>>>>
>>>>
>>>>
>>>> On 5/10/2015 8:10 PM, Roger (K8RI) on TT wrote:
>>>>> On 5/10/2015 2:54 PM, Jon Pearl - W4ABC wrote:
>>>>>> Orlando is right around the corner from you...
>>>>>>
>>>>>> http://www.alro.com/locations/locationsmain.aspx?Loc=FL
>>>>>>
>>>>>>
>>>>> Standard disclaimer:  I have no interest in Alro other than being a
>>>>> satisfied customer
>>>>>
>>>>> I didn't realize they were so wide spread, but Alro has an outlet
>>>>> about 20 miles from me up here in Michigan.Their prices, up here are
>>>>> better than the local supply.  Although I may purchase 10 stock
>>>>> lengths of 1.5" and 2" diameter 6061T6 and DOM steel tube, at times I
>>>>> have called over with a relatively small order that I had planned on
>>>>> picking up.  They delivered it right to my door.  A small order is 
>>>>> not
>>>>> just one piece of mast.  I assume they must have had another, larger
>>>>> delivery in the area.
>>>>>
>>>>> As with large companies with multiple outlets, I assume policies may
>>>>> vary between outlets.
>>>>>
>>>>> 73
>>>>>
>>>>> Roger (K8RI)
>>>>>
>>>>
>>>> ---
>>>> This email has been checked for viruses by Avast antivirus software.
>>>> http://www.avast.com
>>>>
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