October 2, 1989
Refer to: HNG-14/SS-13A
Mr. Mark S. Granger
Sign Post Sales Manager
Marion Steel Company
912 Cheney Avenue
Marion, Ohio 43302
Dear Mr. Granger:
Our letter of August 31 granted acceptance for your company's Rib-Bak sign posts in sizes from 2 to 4 pound-per-foot when used with a lap splice connection. Since copies of this letter were received in our field offices we have received questions regarding the grade of steel used. The report prepared by the Texas Transportation Institute Small sign Support Analysis, stated the steel used in the crash-tested supports "was found to develop the nominal material yield stress (80 ksi) under static bending loads". The 80-ksi reference was used in the attachment to our acceptance letter and has resulted in some confusion.
In order to clarify the issue, we discussed this with you on September 29 at which time you indicated that the steel used is of your own formulation and may be referred to as "SP-80" steel. This steel was designed to meet the chemical and physical requirements cited in Federal Highway Administration's September 27, 1983, Technical Advisory T 5040.22 "Steel Flanged Channel Posts for Small Highway Sign Supports". You stated that Marion Steel found that steel made to this specification uniformly attained a yield strength of 80 ksi, therefore your company certified SP-80 as an 80-ksi yield steel.
We are clarifying this matter with our field offices via copies of this latter.
L. A. Staron, Chief
Federal-Aid and Design Division
Federal Highway Administration
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