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Threaded Pipe Nipple — Factory Direct Supplier | Huaxia-Steel

Huaxia-Steel manufactures and exports threaded pipe nipples from 1/8″ to 4″ NPS in black carbon steel and hot-dip galvanized finish, with NPT, BSPT and BSPP threads cut in-house to ASME B1.20.1 / ISO 7-1. We supply plumbers’ merchants, industrial distributors and OEM assemblers with close nipples, long nipples, swage nipples and reducer nipples in SCH 40 and SCH 80 — factory-direct, with EN 10204 3.1 material certificates and export-ready packaging from 500,000+ pieces per month of capacity.

Product Overview

A pipe nipple is a short length of pipe threaded on both ends (or on one end, “TOE”) used to connect fittings, valves, and equipment in low-to-medium pressure pipework — water, air, gas, oil, steam and fire-protection systems. Unlike butt-welded fittings, threaded nipples allow field assembly with hand tools, which is why they dominate maintenance work, small-bore instrumentation connections, and building services.

Quality in nipples concentrates on three points, and we control all three in-house. Thread accuracy: gauge-checked NPT/BSPT threads that seal on 2–3 turns of tape without cross-threading or excessive slop — a bad thread is a leak. Wall thickness: nipples cut from seamless or ERW pipe meeting SCH 40/SCH 80, not from thin “merchant grade” tube. Galvanizing: threads protected with a post-galvanizing re-tap or thin-coat treatment so the finished joint seals properly — as-galvanized threads that bind on installation are the most common field complaint with cheap imported nipples.

Specifications and Tolerances

ParameterRangeStandard / tolerance
Nominal size1/8″ – 4″ NPS (DN6–DN100)ASME B36.10M dimensions
Wall scheduleSCH 40 (STD), SCH 80 (XS); SCH 160 on request±12.5% wall per ASTM A53
LengthsClose (2.9″–4.5″ by size) to 24″ (610 mm)±1/16″ (±1.6 mm) standard
Thread typesNPT (ASME B1.20.1), BSPT/BSPP (ISO 7-1 / BS 2779)Gauge-checked per piece
MaterialASTM A53 Gr B / A106 Gr B / Q235 equivalentEN 10204 3.1 certificate
FinishBlack (varnished) or hot-dip galvanizedASTM A153-class coating on galvanized
Pressure ratingSCH 40: ~1,000–2,000 psi class by size (cold, water/oil/gas)Confirm per size and service
End typesBE (both end threaded), TOE, swage, reducerThread protectors on request

Thread geometry matters more than buyers expect when mixing suppliers: NPT (60° taper, American) and BSPT (55° taper, ISO) are not interchangeable and mixing them is a common cause of joint failure in imported assemblies. Mark your PO with the thread standard per market, and for dual-market distribution we can package separate NPT and BSPT sub-lots from the same production run.

pipe nipple

Available Types

  • Close nipple: maximum length with threads meeting or nearly meeting in the middle — the most common maintenance item, sizes 1/8″–4″.
  • Long / short nipple: standard lengths from 2″ to 24″ for extending connections between fittings and equipment.
  • Reducing nipple: different thread sizes each end (e.g. 2″ × 1″), for transitions without a reducing coupling.
  • Swage nipple: eccentric or concentric, threaded or plain ends, for alignment in piping runs — SCH 40/80, seamless.
  • Weld nipple: plain beveled end + threaded end, tying threaded systems into welded headers.
  • Galvanized nipple: hot-dip galvanized body with re-tapped threads for potable water and fire sprinkler work.
  • Manufacturing Standards

  • ASTM A733 — standard practice for welded and seamless carbon and stainless steel pipe nipples (dimensions, threads, marking).
  • ASTM A53 / A106 — base pipe material specifications.
  • ASME B1.20.1 — NPT pipe threads; ISO 7-1 — R/Rp parallel-and-taper BS threads.
  • ASME B16.3 / B16.39 — companion malleable-iron and steel threaded fittings (for system compatibility).
  • FM / UL listings — available for fire-protection-market nipples on qualifying production (quote on request).
  • Applications

  • Building services: water supply, HVAC risers, compressed air drops, natural gas branch lines (black iron, SCH 40/80).
  • Fire protection: sprinkler branch lines and test connections (galvanized or black, FM/UL options).
  • Industrial maintenance: gauge glasses, pump suction/discharge spools, lubrication and instrumentation take-offs.
  • OEM equipment: compressor, generator and hydraulic package skids assembled with threaded connections for field serviceability.
  • Quality Assurance

  • Thread gauging: L1/L2 plug and ring gauges per lot; GO/NO-GO acceptance documented.
  • Hydrostatic and air testing of qualifying production lots; material certificates EN 10204 3.1 traceable to heat number.
  • Galvanizing weight and adhesion checks on galvanized lots per ASTM A153 test methods.
  • Visual and dimensional inspection to AQL sampling plans; thread protectors and anti-rust varnish as specified.
  • Third-party inspection (SGS/TÜV/BV) before shipment on request; sampling from sealed production lots.
  • Packaging and Shipping

    Standard export packaging: small sizes in poly bags (10/25/50 pcs) inside double-wall cartons; larger sizes bundle-strapped and capped; all cartons palletized and shrink-wrapped with desiccant for sea transit. Carton and pallet labeling per your barcoding system; private-label cartons available from agreed volumes. Typical loading: 20–24 t per 20 ft container depending on size mix. HS Code: 7307.19 / 7307.99 (threaded pipe fittings of iron or steel) — confirm the heading for your tariff schedule with the packing list we provide.

    Why Source Pipe Nipples From Huaxia-Steel

  • Thread cut and gauged in-house — consistent sealing performance across the whole shipment, not just the sample.
  • Both NPT and BSPT from one factory simplifies dual-market distribution.
  • SCH 40/80 genuine-wall material with certificates, at factory-direct pricing against trader quotes.
  • Mixed-size containers with per-carton packing lists; 20–30 day lead times for standard ranges.
  • Price Factors and Quotation Checklist

    Nipple pricing is driven by size mix, schedule, material and finish. Large diameters and SCH 80 cost multiples of small SCH 40 — a 4″ SCH 80 nipple weighs several times its 1″ counterpart and needs heavier pipe. Galvanized adds a hot-dip step (typically 15–25% over black). Thread standard does not change price but changes tooling setup — order NPT and BSPT as separate line items. Quantity per size matters sharply below about 500 pcs per size, where setup dominates unit cost. Finally, thread protectors, barcoding and private-label cartons are low-cost additions when specified upfront.

    For an accurate first quotation, tell us: size range (NPS × schedule), thread standard (NPT/BSPT/BSPP), length types (close/standard/TOE), material (A53 Gr B or A106 Gr B), finish (black/galvanized), quantities per size, and packing preferences. We will quote factory-direct with certificate samples and confirm gauge inspection documentation.

    Are NPT and BSPT threads interchangeable?

    No. NPT uses a 60° thread angle; BSPT uses 55°. They will start together by force, but the engagement is wrong and the joint leaks or galls under pressure. Mixing them in one system is one of the most common causes of leaking threaded joints in equipment assembled from multi-country components. Mark the thread standard on your PO and on the cartons.

    Why do galvanized nipples sometimes need re-tapping?

    Hot-dip galvanizing coats everything, including threads, and zinc buildup tightens the fit. Quality suppliers re-tap or gauge-sort after galvanizing so the nipple takes tape and seals on first installation. Uncorrected as-galvanized threads are the most common field complaint with low-cost imports — ask explicitly whether re-tapping is in the process, and check a sample on arrival with a GO gauge.

    What pressure can a threaded nipple system handle?

    The joint rating is set by the lowest-rated element — usually the threaded fitting class, not the nipple itself. SCH 40 nipples in standard malleable or forged steel fittings comfortably serve typical water, air, oil and low-pressure steam classes; SCH 80 extends the envelope for higher classes. For each size and service, confirm the rated pressure from the fitting standard (ASME B16.3/B16.11 tables) and derate for temperature — we can provide the table for your size mix on request.

    Common Sizes and Unit Weights

    NPSOD (mm)SCH 40 WTSCH 80 WTKg/100 pcs (2″ long, SCH 40)
    1/2″21.32.77 mm3.73 mm≈ 27 kg
    3/4″26.72.87 mm3.91 mm≈ 39 kg
    1″33.43.38 mm4.55 mm≈ 58 kg
    2″60.33.91 mm5.54 mm≈ 125 kg
    4″114.36.02 mm8.56 mm≈ 470 kg

    Ordering Process and Lead Time

    Standard workflow: send your size/thread/finish list → quotation with thread gauge documentation sample within 48 hours → production with per-lot gauging → pre-shipment inspection → shipment with full packing lists per carton. Standard ranges ship in 20–30 days; FM/UL-qualified production for fire-protection markets is scheduled per campaign — confirm current campaign timing when quoting. Mixed containers across sizes, schedules and finishes are standard; carton labels carry size, thread, schedule and quantity for warehouse put-away without opening.

    Storage and handling on your side protect the quality we ship: keep cartons dry and off concrete floors, rotate stock so older lots install first, and store galvanized product away from untreated timber and acidic environments that attack zinc. Black nipples stored outdoors for more than a season should be re-oiled or indoor-stored — surface rust on threads is the leading cause of installation complaints that trace to storage, not manufacturing.

    Thread seal selection completes the joint design: PTFE tape suits NPT taper threads on water and air service; thread sealant paste fills better on larger sizes and steam work; parallel-thread (BSPP) joints seal on the face washer, not the thread, and should never be taped as if they were taper. Supply the sealing convention with the fitting spec on your RFQ and the assembled system seals on first pressurization — the cheapest possible commissioning outcome.

    For distributors, the practical minimums are worth knowing at quote time: small sizes (1/8″–1″) produce economically from 200 pcs per size; mid sizes (1-1/4″–2″) from 100; large sizes (2-1/2″–4″) from 50. Below those counts, unit prices rise sharply because setup dominates — better to consolidate into stocking quantities on fast movers and quote specials less often.

    pipe nipple

    Get a Factory-Direct Quote for Pipe Nipples

    Send your size range, thread standard and finish for a same-week quotation with sample threads on request.

    Request a quote: Contact Huaxia-Steel.

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