afazz
Well-known member
I'm having some issues flaring 304 stainless tubing.
The tubing I'm using is 304/304L seamless annealed. I'm cutting it with a hacksaw, squaring the edge with a file, deburring with various methods (I thought that was originally my problem) including files, HSS countersinks, cobalt countersinks, rotaburrs, stones, and a Ridgid ID/OD reamer. I'm flaring with a relatively new Imperial 400-F Rol-Air flaring tool. I'm using either ND30 or WD40 for lubricant. I've produced beautiful flares using the same technique and tooling over 40 times on this project alone.
I traced my problems down to the tubing itself, Heat No. Y14014 from the Shanghai Crystal Palace tubing company. I purchased it from ThyssenKrupp OnlineMetals in November 2013. I misplaced the certs.
Here are three flares that I cut off because they weren't acceptable. I was able to get a clean-ish flare by cutting 6" from the tube, but it seems very inconsistent. The problem is not isolated to the 'factory end' of the tubing, I've seen it even near the supplier cut end, which is in the center of a 20' tube.
I cut into the tubing from two different batches, and this is what I found. The inner bore of the 'bad' tubing is all oxidized and porous, while the bore of the 'good' tubing is consistent. Not super smooth like DOM carbon steel, but smooth enough to make good flares. I even tried polishing the ID before making the flare, and it didn't even help.
Before I call the supplier, is there anything I could have done to cause this? Could this be considered normal? I don't think it's corrosion - the tubing was stored standing on end in a heated garage. It's also 304 stainless, which I know isn't perfect, but the OD and all of my other stainless is still corrosion free.
The tubing I'm using is 304/304L seamless annealed. I'm cutting it with a hacksaw, squaring the edge with a file, deburring with various methods (I thought that was originally my problem) including files, HSS countersinks, cobalt countersinks, rotaburrs, stones, and a Ridgid ID/OD reamer. I'm flaring with a relatively new Imperial 400-F Rol-Air flaring tool. I'm using either ND30 or WD40 for lubricant. I've produced beautiful flares using the same technique and tooling over 40 times on this project alone.
I traced my problems down to the tubing itself, Heat No. Y14014 from the Shanghai Crystal Palace tubing company. I purchased it from ThyssenKrupp OnlineMetals in November 2013. I misplaced the certs.
Here are three flares that I cut off because they weren't acceptable. I was able to get a clean-ish flare by cutting 6" from the tube, but it seems very inconsistent. The problem is not isolated to the 'factory end' of the tubing, I've seen it even near the supplier cut end, which is in the center of a 20' tube.
I cut into the tubing from two different batches, and this is what I found. The inner bore of the 'bad' tubing is all oxidized and porous, while the bore of the 'good' tubing is consistent. Not super smooth like DOM carbon steel, but smooth enough to make good flares. I even tried polishing the ID before making the flare, and it didn't even help.
Before I call the supplier, is there anything I could have done to cause this? Could this be considered normal? I don't think it's corrosion - the tubing was stored standing on end in a heated garage. It's also 304 stainless, which I know isn't perfect, but the OD and all of my other stainless is still corrosion free.