Hexagon nipple | A4 | WS 9640
Hex nipple in acid-proof stainless steel A4 (AISI 316), also known as a double nipple, hex nipple, or threaded nipple, is designed for connecting two pipe fittings with internal threads. The nipple features an external tapered pipe thread R (BSPT) according to ISO 7-1 at both ends and a hexagonal center section for tightening with a spanner. The product is used where a leak-proof and corrosion-resistant threaded connection is required, and it is suitable for professional installations where long service life and consistent performance are critical.
APPLICATION AREA
The product is used in plumbing installations, marine environments and boat installations, the process industry, the food and chemical industry, water treatment, and compressed air systems. It is intended for applications where two internally threaded components – for example, sockets, valves, couplings, or T-pipes – are to be connected, and where the choice of material provides the necessary protection against corrosion and mechanical stress. The hex nipple is available in dimensions 1/4", 3/8", 1/2", 3/4", 1", 1 1/4", and 1 1/2".
TECHNICAL SPECIFICATIONS
- Product type: Pipe fitting
- Product family: Hex nipple (double nipple, hex nipple, threaded nipple)
- Material grade: A4 (AISI 316, acid-proof stainless steel)
- Standard: WS 9640, thread according to ISO 7-1
- Thread dimension: R 1/4" – R 1 1/2" (external tapered pipe thread, BSPT)
- Design: Double nipple with hexagon and external thread at both ends
- Surface finish: Bright, untreated
- Environment: Marine / Outdoor / Indoor
- Delivery unit: Piece
FREQUENTLY ASKED QUESTIONS (FAQ)
What is a hex nipple?
A hex nipple (double nipple) is a short pipe fitting with an external thread at both ends and a hexagon in the middle. It is used to connect two parts with internal threads, such as a socket and a valve. The hexagon allows the nipple to be tightened using a standard spanner or adjustable wrench.
How do I choose the right dimension?
The dimension is specified in inches and refers to the nominal size of the pipe thread, not the actual outer diameter of the thread. For example, a 1/2" nipple has a thread diameter of approximately 21 mm. Measure the outer diameter of the thread and compare it with a thread table for BSP threads, or check the dimension of the part into which the nipple is to be screwed.
How do I make the threaded connection tight?
The R-thread is tapered, which means the threads wedge together when the nipple is tightened into an internal thread. For a leak-free connection, a sealant is normally used, such as PTFE tape, hemp with sealing paste, or an anaerobic thread sealant intended for stainless steel.
What is the difference between A2 and A4 for pipe fittings?
A4 (AISI 316) contains molybdenum, which provides better resistance to chlorides and pitting corrosion than A2 (AISI 304). A4 is therefore called acid-proof and is the recommended choice in saltwater, marine environments, pool environments, and in contact with chemicals.