Tape Measure Markings

Date: 08/11/97 at 11:10:39
From: Anonymous
Subject: Tape measure

As a construction worker for years, I have noticed that there is a 
small diamond (or triangle according to the brand) on all tape 
measures every 19.2 inches, much like the mark at 16 inches (for 
marking the placement of studs at 16" on center).  I had first thought 
that it was 1/10th of a rod, as 10 of the marks equals 16 feet (192 
inches), but a rod is equal to 5 1/2 yards (16.5 feet).  It is not 
really an important issue here, but just something that keeps 
bothering me, not knowing what it is for, and also knowing that it
is put there for a reason, for some sort of measurement.  Any help 
would be greatly appreciated.  

Thanks!   

- Greg

Date: 08/11/97 at 11:46:44
From: Johnny Hamilton
Subject: Re: Tape Measure

The diamonds or triangles are for placing five studs in a wall over 
an eight foot space rather than four or six studs. 

If you divide five into 96 inches, it will give 19.2 inches. In other 
words, 4 into 96" = 24", 5 into 96" = 19.2", and 6 into 96" = 16". 
These are the normal centerings of wall studs.

- Johnny

Johnny E. Hamilton <jhamilton@constructpress.com>
Construction Trades Press
http://www.constructpress.com/   
Publishers of Math to Build On and Pipe Fitter's Math Guide