Stainless Steel Fittings
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      1. Boshart Knowledge Base
      2. Stainless Steel Fittings

      Making a Leak Proof Stainless Steel Threaded Connection

      Boshart Industries highly recommends the use of our GRAY STAINLESS STEEL TEFLON TAPE and GRAY MAGIC PIPE THREADED COMPOUND together for the joining of all Stainless-Steel fittings, nipples, and well supplies with NPT threads.

      STAINLESS STEEL THREAD SEALING - Due to the extreme hardness of stainless alloys, and the issues regarding galling, the sealing of S.S. threaded connections can be much more challenging than when working with brass or bronze alloy fittings. The following information will greatly reduce the problems and frustration that first time users of stainless fittings and accessories sometimes have. The information below explains the issues with sealing stainless to stainless thread connections, and will greatly reduce the learning curve, ensuring a smooth transition into using stainless steel products.

      GALLING -  What is galling? Stainless steel fittings exhibit many desirable properties, but a common problem is seizing or pick-up on assembly or disassembly. This phenomenon is known as galling. It is thought to be caused by cold welding of the high points of clean, oxide free metal left when the oxide film is dislodged by surfaces rubbing against each other, especially when threading mated parts of the same grade and surface hardness.

      SOLUTIONS!

      GRAY STAINLESS STEEL PTFE THREAD SEAL TAPE

      This tape has a gray colored, nickel pigment added for use on all stainless-steel fittings. Specially designed to prevent galling, seizing, and corrosion. A quality tape with a high-density rating makes this tape an excellent product for sealing coarse stainless steel pipe threads.

      Part Number: TT260-SS (1/2" x 260"x .004")

      GRAY MAGIC PIPE THREAD COMPOUND

      Gray Magic is an all purpose, non-seizing, industrial grade thread sealing compound that produces a leak-proof seal on all types of plastic and metal including stainless steel threaded connections having superior anti-galling properties. Gray Magic is a non-toxic, smooth, grit-free, completely homogenized, gray industrial grade paste.

      Part Numbers: TS-GM08 (8 OZ), TS-GM16 (16OZ) & TS-GM32 (32OZ)

      DIRECTIONS FOR USE:

      #1 Stir well before using.

      #2 Brush liberally onto male threads.

      #3 Make up joint in a normal manner.

      INSTALLATION TIP – To ensure leak-proof connections in stainless steel it has been proven and is highly recommended that the installer first wraps the pipe threads with two or more thicknesses of GRAY STAINLESS STEEL PTFE THREAD SEAL TAPE then apply GRAY MAGIC over the tape. This is a practice that is necessary on large diameter stainless pipes 4" and up. It has been proven to be very effective in preventing leaks in all sizes of stainless-steel threaded connections!

      CAUTION: NPSM and NPTF threads

      P.T.F.E. Thread Seal Tape or Thread Sealing Compounds such as Gray Magic are not for sealing NPSM threads which is a straight thread with the same 60-degree angle as the NPT tapered pipe thread. NPSM threads can not form a seal using its thread, it needs an O-ring to form a seal.

      The same is true for NPTF-to-NPTF joints (Dry Seal Threads) which create a strong, leakproof mechanical seal without using a sealant. Merchant steel fittings have NPTF (ASME B1.20.3) threads which are compatible with NPT threads. See the link below for more detail on making connections with NPFT threads.

      https://support.boshart.com/are-merchant-steel-fittings-with-nptf-asme-b1.20.3-threaded-compatible-with-npt