Carbon Steel Pipe Nipple — Factory Direct Supplier | Huaxia-Steel

A carbon steel pipe nipple is a short length of pipe with male threads on both ends, used to connect two female-threaded fittings or valves. It is one of the most common accessories in low-pressure plumbing, fire protection, compressed air, fuel oil and industrial piping systems. Huaxia Steel supplies carbon steel pipe nipples in NPT, BSPT and BSPP threads to ASTM A53, ASTM A106 and API 5L requirements, with black, galvanized or custom surface finishes.

Product Overview

Pipe nipples are cut from seamless or welded carbon steel pipe and threaded on both ends. They are classified by length, thread type, material grade and surface finish. Common types include close nipples, barrel nipples, running nipples, hex nipples, long hex nipples, reducing nipples and welded nipples. Standard lengths range from 1″ close nipples to 72″ long barrel nipples, with custom lengths available on request.

Typical Specifications

Parameter	Range / Value
Standard	ASTM A53, ASTM A106, API 5L, ASME B1.20.1, ISO 7/1, BS 21
Nominal size	1/8″ – 6″ (DN6 – DN150)
Length	Close (1″) up to 72″ (custom on request)
Thread type	NPT, BSPT, BSPP
Pressure rating	150 psi – 3,000 psi depending on schedule and grade
Wall thickness	Sch 40, Sch 80, Sch 160, XS, XXS
Material grades	A53 Gr.B, A106 Gr.B, API 5L Gr.B, A105 (forged nipples)
Surface finish	Black, hot-dip galvanized, zinc plated, plain oil

Common Types of Pipe Nipples

Type	Description	Typical use
Close nipple	Threaded full length, no unthreaded barrel	Tight spaces between two fittings
Barrel nipple	Short unthreaded section in the middle	General pipe extensions
Running nipple	Long unthreaded section with threads only at ends	Longer extensions through walls or tanks
Hex nipple	Hexagonal center section for wrench grip	Fittings where tightening is needed
Reducing nipple	Different sizes at each end	Connecting pipes of different diameters
Welded nipple	One welded end, one threaded end	Transitions to welded systems

Thread Standards

The most common thread standard for carbon steel nipples is NPT (National Pipe Thread Taper) per ASME B1.20.1. NPT threads seal by deformation of the threads and require thread sealant. BSPT threads per ISO 7/1 are tapered and common in European and Commonwealth markets. BSPP threads are parallel and require a gasket or O-ring seal. Always specify the thread type in your purchase order to avoid mismatched connections.

Applications

Plumbing and water distribution systems
Fire protection sprinkler and standpipe systems
Compressed air lines and pneumatic systems
Fuel oil and LPG transfer lines
Steam heating and low-pressure process piping
HVAC chilled and hot water lines
Industrial equipment connections and maintenance spares

Quality Assurance

Each batch is checked for thread gauge fit, thread length, surface finish, dimensional tolerance and material traceability. Seamless nipples for high-pressure service are hydrostatic tested when required by the standard. Mill test certificates are available for all pressure-rated nipples. Third-party inspection by SGS or BV can be arranged for critical projects.

Packaging and Shipping

Pipe nipples are bundled by size and thread type, then packed in wooden crates or strong cardboard cartons for export. Threads are protected with plastic caps. Black nipples receive a light oil coating; galvanized nipples are packed dry. Labelling includes size, length, thread standard, material grade, heat number and quantity.

Why Buy Carbon Steel Pipe Nipples from Huaxia Steel

Precision NPT, BSPT and BSPP threading
Seamless and welded options in Sch 40, Sch 80 and custom schedules
Black, galvanized and zinc-plated finishes
Custom lengths and special nipple types on request
Mill test certificates and third-party inspection available

Request a Quote

Tell us the size, length, thread type, schedule, grade, finish and quantity. We will confirm pricing, lead time and packing details. Contact Huaxia Steel for carbon steel pipe nipple pricing today.

Manufacturing Process

Carbon steel pipe nipples are manufactured from seamless or welded pipe. The pipe is cut to length, deburred and chamfered. Threads are cut on CNC lathes or rolling machines to the required standard. After threading, the nipples are cleaned, inspected with ring and plug gauges, and given a protective coating such as black oxide, oil or zinc plating.

Pipe cutting to length
End deburring and chamfering
Thread cutting or rolling
Gauge inspection
Cleaning and surface treatment
Thread protection and packaging

Inspection and Testing

Each batch is inspected for thread form, thread length, diameter, length and surface finish. For pressure-rated nipples, hydrostatic testing is performed on the source pipe. Material traceability is maintained through heat numbers recorded on the mill test certificate.

Pressure Rating Reference

Schedule	Class 150 psi	Class 300 psi	Class 600 psi
Sch 40	Up to 2″ NPS	Up to 2″ NPS	Limited sizes
Sch 80	2″ – 6″ NPS	2″ – 6″ NPS	2″ – 4″ NPS
Sch 160	Not typical	Not typical	Heavy wall

FAQ

What is the difference between a nipple and a coupling?

A nipple is a short piece of pipe with male threads on both ends. A coupling is a short fitting with female threads used to join two male-threaded pipes or fittings.

Are galvanized nipples suitable for drinking water?

Galvanized nipples were historically used for water lines but are now restricted in many countries for potable water due to zinc leaching. Check local plumbing codes before specifying.