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			#25  
			
			
			
			
			
		 
		
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			Hi Martyn. 
		
		
		
			I just measured my original smoke discharger. I can confirm the O/D is 4.5" and I/D 4" therefore wall thickness =1/4" However the length of mine is nearer 9.5"....oow err missus! Not sure what you mean about the nut? It's a nut with a hex on the back edge and heavy splined edge at the front for finger tightening. I can't remember what thread it is, but I can check if necc. I can also give dimensions of the nut if required. Have a look at the state of my mounting bracket. I think it came from a carrier in Pounds yard that the tide had been coming in and over for years. Ron  | 
		
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