[TowerTalk] Is this pipe or mast

[force12@interserv.com]

OK - another 2 cents worth here (and not going into a lot of detail):

Pipe indeed, is pipe. The size specification on pipe is the approximate 
inside diameter and the wall thickness is determined by the "schedule NN" 
figure (the higher the number, the thicker the wall: SCH 10,40,80). The wall 
thickness for each diameter pipe is not the same for the same schedule NN. 
The actual inside diameter, as mentioned, is "approximate" and varies within 
the same pipe size with the wall thickness.
	For example:
Pipe Size	Actual OD	SCH	Wall Thickness	Theoretical ID
1 1/2"		1.900"		5	.065"		1.770"
				10	.109"		1.682"
				40	.145"		1.610" 		
				80	.200"		1.500"
2"		2.375"		10	.109"		2.157"
				40	.154"		2.067"
				80	.218"		1.939"
2 1/2"		2.875"		10	.120"		2.635"
				40	.203"		2.469"
				80	.276"		2.323"



Tubing is round tubing. The size specification on tubing is the outside 
diameter and the wall thickness is specified directly. To know the inside 
diameter, one must subtract twice the wall thickness from the tubing 
diameter (outside diameter). For example, 1" diameter tubing with a .058" 
wall is approximately 0.884" inside diameter, which is a bit larger than 
7/8" (0.875" diameter) tubing, and should telescope into it. The word 
"should" is used, because tolerances need to be taken into account. Drawn 
tubing has closer tolerances than extruded.

Other than round, enclosed products are usually referred to as "shapes". 
Shapes includes square and rectangular. Shapes are specified in the outside 
dimensions and also have a wall thickness spec. 


W0UN properly cautioned that not only do you need the alloy type (i.e. 
6061), you need the heat treatment spec (i.e. T6)



Have a good day and 73,
			Tom, N6BT
			Force 12 Antennas and Systems
			(Home Page   http://www.QTH.com/force12 )



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