Here's a puzzle of sorts. Today, I found two rebars, both supposedly marking the same angle point on a lot boundary in a subdivision originally surveyed between December, 1962 and April, 1964. Both of the two rebars had bits of old plastic flagging on them. One is most likely the original monument shown on the plat and the other is not.
Here's a photo of one after removing it to inspect it and a bit of wire brushing to clean it up for examination. What is the earliest date that this rebar could plausibly have been set in that Central Texas subdivision?
1923 when turkey was formed as the modern Republic of Turkey as we know it now. granted it wouldnt have been monumenting the subdivision corner that was created after 1962...lol so for the rebar to have been in the US legally it would have had to follow the 1963 entrance into the european economic community and the involvement in the ECSC european coal and steel community.. so the genuine date has to be some time after 1963 unless the rebar was smuggled into the US.
1962
1974
does that say it was manufactured in April 1960? So earliest date it could have been set would have been December 1962?
So how do you approach rebar examination when they are extremely rusted such that identifiers are no longer discernible?
> 1974
Well US Department of Commerce data indicate that rebar was first imported into the US from Turkey in November, 2000, for starters.
> does that say it was manufactured in April 1960? So earliest date it could have been set would have been December 1962?
>
> So how do you approach rebar examination when they are extremely rusted such that identifiers are no longer discernible?
The mill mark is "4 60 TURKEY S CM". The "4" refers to the bar size, i.e. #4 or 13mm rebar. The "60" means the steel is grade 60, nominally 60 ksi yield strength steel which earlier was uncommon, most of the bars being grade 40 or 40 ksi steel. Now the "S" could be the designation that means it was rolled from billet steel or it could be part of the mill designation "SCM" which would belong to a Ukrainian company that began operations in Turkey in about 2005.
As for the sort of information that you can get out of a rebar when there is no mill mark on the piece, that depends. The pattern of deformations will sometimes date older bars. The tool marks on the cut ends can provide a basis for comparing with other bars supposedly set at the same time during the same survey. Likewise, length is a somewhat similar clue.
If you need to do it, you can always get a metallurgy lab to test the steel in the bar as a way of showing whether they are quite dissimilar or not.
> > does that say it was manufactured in April 1960? So earliest date it could have been set would have been December 1962?
> >
> > So how do you approach rebar examination when they are extremely rusted such that identifiers are no longer discernible?
>
> The mill mark is "4 60 TURKEY S CM". The "4" refers to the bar size, i.e. #4 or 13mm rebar. The "60" means the steel is grade 60, nominally 60 ksi yield strength steel which earlier was uncommon, most of the bars being grade 40 or 40 ksi steel. Now the "S" could be the designation that means it was rolled from billet steel or it could be part of the mill designation "SCM" which would belong to a Ukrainian company that began operations in Turkey in about 2005.
>
> As for the sort of information that you can get out of a rebar when there is no mill mark on the piece, that depends. The pattern of deformations will sometimes date older bars. The tool marks on the cut ends can provide a basis for comparing with other bars supposedly set at the same time during the same survey. Likewise, length is a somewhat similar clue.
>
> If you need to do it, you can always get a metallurgy lab to test the steel in the bar as a way of showing whether they are quite dissimilar or not.
I admire with your ability to be facinated with the metal and year model of rebar. Pretty cool detective story...also I like the idea of having the corners sent to the lab for testing.
> ...also I like the idea of having the corners sent to the lab for testing.
I've never actually had to do it, but it is always a possibility. Your best bet is the simple, obvious stuff like mill marks, tool marks on cut ends, patterns of deformations, and lengths.
I've always been amazed at some of the stuff that comes from us surveyors. But I will suggest that discerning the birth date of a rebar far exceeds the importance of the missing 0.04 ft, or even the whereabouts of Hub Northing. God rest his soul....
Regardless, my guess is the guy had the bar flipped upside over and it really is "09" and not "60". (thats older) Then he got back from his smoke break and fixed the other ones. Check the back corners for similar markings...