Steel Welding Flanges are available in several sizes.  Please note the bolt pattern differs depending on which size you choose.  Each of the steel welding flanges are 1/2″ OD Pipe Size.

2″ Welding Flange  
Pipe Size = 2″
OD = 6″
Thickness = 1/2″
Bore = 2.06″
# of Holes = 4
2-1/2″ Welding Flange
Pipe Size = 2-1/2″
OD = 7″
Thickness = 1/2″
Bore = 2.56″
# of Holes = 4
3″ Welding Flange
Pipe Size = 3″
OD = 7-1/2″
Thickness = 1/2″
Bore = 3.06″
# of Holes = 4
4″ Welding Flange  
Pipe Size = 4″
OD = 9″
Thickness = 1/2″
Bore = 4.06″
# of Holes = 8
5″ Welding Flange  
Pipe Size = 5″
OD = 10″
Thickness = 1/2″
Bore = 5.06″
# of Holes = 8
6″ Welding Flange  
Pipe Size = 6″
OD = 11″
Thickness = 1/2″
Bore = 6.06″
# of Holes = 8
7″ Welding Flange  
Pipe Size = 7″
OD = 11″
Thickness = 1/2″
Bore = 7.06″
# of Holes = 8
8″ Welding Flange  
Pipe Size = 8″
OD = 13-1/2″
Thickness = 1/2″
Bore = 8.06″
# of Holes = 8
10″ Welding Flange  
Pipe Size = 10″
OD = 16″
Thickness = 1/2″
Bore = 10.06″
# of Holes = 12
12″ Welding Flange  
Pipe Size = 12″
OD = 19″
Thickness = 1/2″
Bore = 12.06″
# of Holes = 12
OD = Outside Diameter Pierce Logo

Brand Name: Pierce