Welding Procedure Development for 1/8" HSS
Welding Procedure Development for 1/8" HSS
(OP)
I'm working in Canada and a Client wants me to develop an approved welding procedure for splicing HSS square tubing but these are my limitations.
The HSS square tubing dimensions are 1"x1"x1/8",
The splice would be a corner so i cant use a backing bar. (two HSS cut on 45deg fused together to make a 90deg corner),
and they want it to be a Partial Penetration Joint to avoid the use of "T" Class welders for CJP as per CSA W47.1.
Any suggestions?
The HSS square tubing dimensions are 1"x1"x1/8",
The splice would be a corner so i cant use a backing bar. (two HSS cut on 45deg fused together to make a 90deg corner),
and they want it to be a Partial Penetration Joint to avoid the use of "T" Class welders for CJP as per CSA W47.1.
Any suggestions?





RE: Welding Procedure Development for 1/8" HSS
Mike McCann
MMC Engineering
Motto: KISS
Motivation: Don't ask
RE: Welding Procedure Development for 1/8" HSS
1x1x1/8 thick sq tubing is very thick, but you really don't have much metal there for any kind of "weld prep."
If you have 14 gage steel walls like I use for railing and frames, you can't really make any prep at all. Just fuse the two touching steel, working very hard not to burn through the wall. 1/8 will be a bit easier to work with, but I'd worry much, much more about burning through and having to frequently "fill in" the hole rather than worry about the prep.
A conventional 1/8 steel prep on the sides will have a 1/16 flat, then a 1/16 "bevel" - very difficult to machine accurately. (The 45 degree cut of both tubes is more important for your fitup!) Your first pass will completely fill the joint. Assume a weld heat or feed rate of 2 is used.
On the inside corner, your welders will have a fillet joint that will tend to either burn through or not get good fusion into both tubes. Access won't be easy. If they use a MIG welding process, they will have to swing the nozzle across the joint to get the base metal in both tubes melted. on this corner, maybe a slightly slower speed, but a slightly higher wire feed rate or slightly higher heat input.
On the outside, you will melt and round off the very skinny corner. Here they will need to reduce heat, reduce feed rate of the wire, and work very hard not to make holes.
Remember, the purpose of the bevel in the weld prep is to ensure your welders can reach the inside of the weld on the first pass. If you have a process spec for welding thin carbon steel, you don't need another. Just practice and isstruction.
RE: Welding Procedure Development for 1/8" HSS