1" x 3-1/2" Stainless Steel Nipple

Couple of thoughts based on other reviews- (I have purchased merit brass domestic stainless nipples before as well) Loctite 567 specifically is not for use on plastic fittings. It cures by metal to metal anaerobic contact. No two npt threads are cut exactly alike- particularly between manufacturer's. If you can't tell the difference it's because you can't measure precisely enough. Some are wildly different, some are almost identical. Sealing NPT threads is somewhere between art and science. I find these to be pretty good for the price charged and being domestically sourced. Sometimes they need a little cleanup with a file or passing a die over them a little further. It is what it is.

I am very pleased with all the Merit and other stainless steel fittings I received. And the customer service at SupplyHouse was excellent as usual. I read some reviewers criticize stainless fittings due to galling. USE THE CORRECT SEALANT and this will probably not happen. DO NOT use teflon tape on stainless. Use tape made for stainless. Typically the tape contains nickel.and may cost 20 or more times that of PTFE. Also I use a paste thread sealant made for stainless. I have not had any galling in years.

These products are suitable and a fair price. The only complaint I have is that it was back ordered for a considerable period.

The threads on these nipples are very different than the Chinese ones which I also bought. Turns out that was a wise decision. The rate at which the threads taper on these is MUCH faster than on the Chinese ones. I measured both starting and end O.D. and they are the same. But the Chinese ones taper much more slowly. In my case, I wanted to put on a brass 1" to PEX barb 3/4" Swivel adapter (SKU UC594LF) the nature of the taper on these nipples made that simply impossible. The swivel could simply never tight up enough to stop jiggling loosely in my fingers. I switched to the Chinese ones and that was not a problem. For some applications, these may be perfect. But for what I wanted, they were awful.

I have put a lot of stainless steel pipe together, I religiously use locktite 567 pipe dope when using threaded fittings. These fittings were very hard to get to stop leaking. After inspecting the threads on the first few that leaked it appeared that the threads were not cut completely, the last 5 threads were flat on top. I have a lot of other size fittings that sealed up with no issues. Just these nipples that I had trouble with. They do not appear to thread up as far as the other fittings. I have almost deformed the nipple trying to screw it in farther. They are polished up nicely and other than the flat spots on the threads they look great.

I used the nipples to connect to Poly Triple Action Hard Water Filter which has threads that were a mix of both NPT and BSP. It did require extra teflon tape. Plastic fittings leaked and this is better than galvanized.