Stainless Steel Weld Nipple Male Thread Pipe Fitting 1/4"-4"

Match the nominal pipe size (NPS) to your existing pipe or fitting. For example, a 1/2" weld nipple fits a 1/2" NPT female port. Measure the outer diameter of your pipe and cross-reference a standard NPS chart — a 1/2" NPS pipe has an OD of approximately 0.840" (21.3 mm). When in doubt, size up; a slightly larger fitting is generally easier to adapt than one that is too small.

A properly welded and threaded stainless steel nipple is typically rated for several hundred PSI of working pressure, depending on size and wall thickness. The weld joint, when executed correctly, is generally as strong as the base pipe material itself. Always verify pressure ratings with your system engineer for critical or high-pressure applications.

Yes. 304 stainless steel offers solid resistance to atmospheric corrosion, moisture, and many mild chemicals, making it generally suitable for outdoor plumbing, food-processing environments, and marine-adjacent installations. For highly aggressive chloride or acidic environments, 316 stainless steel is typically recommended instead. If you are unsure which grade fits your application, contact us before ordering.

These weld nipples feature male NPT (National Pipe Taper) threads, which are the standard tapered thread used throughout North American plumbing and industrial piping systems (ANSI/ASME B1.20.1). They are not compatible with BSP (British Standard Pipe) threads without an adapter. Check your existing female port markings before ordering.

Yes, for liquid or gas service. Applying PTFE thread tape or a pipe thread sealant compound to the male threads before assembly is strongly recommended. NPT threads seal by thread interference and taper engagement, and sealant ensures a leak-free joint, especially under pressure. Wrap PTFE tape clockwise (when facing the thread end) for 2–3 layers.

A weld nipple is designed to be welded directly into a tank wall, vessel, or pipe header — one end is prepared for welding and the other end is threaded for a male NPT connection. A standard pipe nipple is threaded on both ends and is not intended for direct welding into a vessel. If you need a threaded port on a tank or custom fabrication, a weld nipple is the correct choice.

Most household water supply lines use 1/2" or 3/4" NPT connections. Garden hose fittings are typically 3/4" GHT (garden hose thread), which differs from NPT — an adapter may be needed. For residential plumbing tie-ins, 1/2" or 3/4" weld nipples are generally the most commonly used sizes. If you are tapping into a main supply line, 3/4" is typically the right starting point.