What is the maximum tube length single-piece?

6,000 mm for most standard tubes. For HP-Nb reformer tubes with smaller OD, up to 14 meters single-piece. Longer assemblies joined by tube-to-tube welding.

What is typical lead time?

Standard catalog tubes: 25-35 days. Custom-spec with new tooling: 40-60 days. Large bore or heavy castings: 50-75 days.

No fixed piece-count MOQ. Standard sizes ship from 1 piece. New tooling economical at 5-10 tubes of same geometry.

Do you ship worldwide?

Yes. Active shipments to 40+ countries including US, UK, Germany, France, Russia, South Korea, Japan, Saudi Arabia, UAE.

Centrifugal Cast Tubes & Pipes | 100-1800mm OD Stainless & Alloy — Kbear Metal

CENTRIFUGAL CAST TUBES & PIPES · SINCE 1989

Leading Centrifugal Cast Tubes & Pipes — 100-1,800 mm OD Stainless, Alloy & Heat-Resistant Grades

Q: What is the difference between centrifugal cast tubes and seamless tubes?

Seamless tubes are made by hot-piercing solid billet - economical for smaller diameters under 200 mm. Centrifugal casting is standard for 100-1,800 mm OD, heat-resistant alloys, wear-resistant alloys, and tubes longer than economical seamless production.

Q: What OD range can you centrifugally cast?

100 mm to 1,800 mm OD on horizontal line, 200 mm to 1,500 mm OD on vertical line. Below 100 mm seamless is more economical. Above 1,800 mm requires custom mold tooling.

Q: Can you do pressure testing for tube castings?

Yes. Hydrostatic pressure testing per ASME B31.3 at 1.5x design pressure. Test certificates issued per tube with serial number.

Q: What surface finish can you achieve?

As-cast OD: Ra 6.3-12.5 micrometers. After machining: Ra 1.6-3.2 micrometers standard. ID after rough machining: Ra 3.2-6.3 micrometers.

Q: Can you cast tubes with flanges as one piece?

Yes. Flanged tubes are a specialty product. Single-piece casting eliminates flange-to-pipe weld joint. Available with raised face, flat face, or ring-type joint.

Q: What alloy families do you cast?

Seven major families: stainless, HP series, HK series, nickel alloys, heat-resistant, wear-resistant, and copper/bronze. Custom chemistry also produced.

Kbear Metal manufactures centrifugally cast tubes and pipes in stainless steel, HP40, HK40, nickel alloy, heat-resistant, and wear-resistant grades. From 100 mm to 1,800 mm OD, up to 6,000 mm length, single-piece casting eliminates butt-weld failure points. ASTM A608 / A351 documentation per batch.

Get Tube Quote → Send Tube Drawing

1,800mm

Max OD

6 m

Max Length

8,000 kg

Max Per Piece

// Tube & Pipe Spec

OD Range100 – 1,800 mm

Wall Thickness10 – 150 mm

LengthUp to 6,000 mm

Max Weight8,000 kg / piece

Alloy Families7 major groups

StandardsASTM A608 · A351 · A744

Lead Time25 – 45 days

35y

Since 1989Tube & pipe production

A608

ASTM A608 / A351Standards certified

40+

40+ MarketsUS · EU · MENA · APAC

EN3.1

EN 10204 3.1Mill cert per batch

// Tube & Pipe Capability

Metrics that matter for industrial tube buyers

Hard numbers that define what we can supply for centrifugally cast tube and pipe projects.

1,800mm

Max Outer Diameter

Largest OD achievable on our horizontal centrifugal casting line.

100mm

Min Outer Diameter

Smallest economic OD. Below 100mm, seamless tube is preferred route.

6,000mm

Max Single-Piece Length

Eliminates butt-weld failure points common in fabricated pipes.

8,000kg

Max Tube Weight

Per-piece weight limit on our 1,800 mm bore casting machines.

10-150mm

Wall Thickness Range

From thin-wall pipes to heavy-section structural castings.

±0.5mm

OD Tolerance

As-cast OD held within ±0.5 mm. Tighter via post-machining.

Alloy Families

Stainless, HP, HK, nickel, heat-resistant, wear-resistant, copper.

25-45

Lead Time (days)

Standard catalog tubes from confirmed PO to packed export crate.

// Tube & Pipe Types

Six tube and pipe configurations under one roof

Straight tubes, flanged, tapered, asymmetric — all cast as single-piece centrifugal castings.

// 01

Flanged Straight Tubes

Pipeline tubes with integral cast flanges. Single-piece casting eliminates flange-to-pipe weld joints.

1-pieceNo weldsUp to 6m

// 02

Tapered Tubes

Variable-OD tubes for transitions and adapter sections. Cast taper from 5° to 30° per side.

5°-30°Custom taper

// 03

Standard Straight Pipes

Constant-OD process pipes for chemical, petrochemical, and high-temperature service.

StainlessAlloyHR

// 04

Heavy-Wall Tubes

Thick-wall tubes for pressure containment and structural service. Up to 150 mm wall thickness.

150mm wallPressure

// 05

Special-Shaped Tubes

Asymmetric, multi-stepped, and complex-profile tubes cast as single piece from buyer drawing.

CustomCAD-based

// 06

Hollow Bars

Heavy-OD hollow bars for further machining into rings, sleeves, gears, and bearing housings.

OD up to 1,800mm

// Tube & Pipe Manufacturing

From melt to packed tube — eight controlled stages

Full documentation chain maintained from chemistry verification through final machining.

Drawing Review & DFM

Engineering reviews buyer drawing or sample. Material recommendation, mold design, and lead time returned in 48 hours.

Mold Prep

Sand or metal mold selected per OD, alloy, and quantity. Mold preheat 200-400°C, surface coating applied.

Melt & Chemistry

Induction furnace melts at 1,500-1,600°C depending on alloy. Spectrometer verifies chemistry pre-pour.

Centrifugal Pour

Mold at 200-1,500 RPM matched to OD. Tundish controls pour rate; centrifugal force distributes alloy.

Cooling & Demold

Controlled cooling profile prevents thermal cracking. Demold; ID rough-machined to remove impurity layer.

Heat Treatment

Solution anneal, normalize, or stress-relief per alloy spec. Documented thermal profile per batch.

NDT Inspection

UT, X-ray, dye-penetrant per ASTM E165/E709. Hydrostatic pressure test for pressure-service tubes.

Machine & Pack

OD/ID finish-machined to drawing tolerance, heat number stamped, end-protected, crated for export.

// Tube & Pipe Alloys

Seven alloy families for centrifugal cast tubes

Material verified by spectrometer on every melt. Mill certificates per EN 10204 3.1 ship with every batch.

// SS

Stainless 304H / 316L

Standard process piping, chemical service.

// HP

HP40 / HP-Nb

High-temp reformer and furnace tubes.

// HK

HK40 / HK45

Ethylene cracking, pyrolysis service.

// Ni

Inconel 625 / 800H

Severe heat & corrosion service.

// HR

1.4848 / 1.4865

EU heat-resistant designations.

// WR

High-Cr Cast Iron

Wear-resistant tubes for mill rolls.

// Cu

Aluminum Bronze

Marine, bearing, low-friction service.

// Custom

Buyer-spec

Project-specific chemistry per drawing.

// Tube & Pipe Specifications

Centrifugal tube envelope by alloy family

Standard envelope. Custom dimensions and chemistry quoted on a project basis.

Parameter	Stainless	HP/HK Alloy	Nickel Alloy	Wear-Resistant
OD Range	100-1,800 mm	80-350 mm	100-800 mm	200-1,500 mm
Wall Thickness	10-100 mm	8-25 mm	10-80 mm	30-150 mm
Max Length	6,000 mm	14,000 mm	4,000 mm	3,500 mm
Max Weight	5,000 kg	1,200 kg	3,500 kg	8,000 kg
Max Service Temp	900°C	1,150°C	1,200°C	Wear duty
Surface Finish (Ra)	1.6-3.2 μm	1.6-3.2 μm	3.2-6.3 μm	3.2-6.3 μm
Standard Reference	ASTM A351	ASTM A608	ASTM A494	ASTM A532
Lead Time (days)	25-40	35-55	40-60	30-50

Need centrifugal cast tubes for a custom project?Send your spec sheet or sample tube — DFM feedback inside 48 hours.

Send Tube Spec →

// Quality Assurance

Documentation chain that passes procurement audits

Industrial tube failures stop production lines. Our QC team builds the documentation package alongside production — chemistry verified before pour, NDT before machining, pressure tested before crating.

A608

ASTM A608 / A351Heat-resistant & stainless

3.1

EN 10204 3.1Mill cert per batch

PED

PED 2014/68/EUEU pressure equipment

SGS

SGS / BV / TÜV3rd-party witnessed

Spectrometer Chemistry

Every melt verified by ladle spectrometer before pour. Re-melt if off-spec.

100% UT Inspection

Ultrasonic on every tube — not statistical sampling. Defects flagged pre-machining.

Hydrostatic Pressure Test

1.5x design pressure per ASME B31.3 for pressure-service tubes.

Dimensional CMM

Coordinate measuring on first article and AQL sampling per shipment.

Heat Number Trace

Every tube stamped with heat number traceable to ladle sample and raw material certs.

// Tube & Pipe Applications

Where centrifugal cast tubes ship from our factory

Eight industries where centrifugally cast tubes are the standard manufacturing route.

Petrochemical Process

Process piping for high-temperature refinery and petrochemical service.

// HP40 / SS

Power Generation

Boiler tubes, superheater supports, gas turbine inlet components.

// Inconel

Steel Mill

Furnace roll shells, walking-beam furnace internals, slide-bearing sleeves.

// WR alloy

Chemical Plant

Stainless process piping for chemical, pharmaceutical, food processing.

// 316L · 304H

Cement & Mining

Kiln roller shells, mill liners, abrasion-resistant sleeves.

// High-Cr

Glass Manufacturing

Glass plant furnace rolls, forehearth components, handling equipment.

// Heat-resistant

Marine & Offshore

Aluminum bronze tubes for marine, offshore, and seawater service.

// Al-Bronze

General Industrial

Hollow bar feedstock for downstream machining into rings, sleeves, gears.

// Custom alloy

Need a sample tube for evaluation?Sample cut from our standard tube stock — pay only courier shipping.

Request Sample →

// Watch Tube Production

See how a centrifugal cast tube gets made

Three short videos covering melt, casting, and quality verification at our Pingdu factory.

02:54

// 01 · Cast

Stainless Tube Centrifugal Pour

304H stainless steel melt poured into mold spinning at 600 RPM. Centrifugal force distributes alloy.

02:08

// 02 · Heat Treat

Solution Anneal & Quench

Tubes solution annealed at 1,050-1,150°C per alloy spec, then rapid quenched for final microstructure.

02:18

// 03 · Machine & Pack

CNC Finish Machining

OD turned and ID bored to drawing tolerance, then heat number stamped and crated.

// Tube & Pipe FAQs

Buyer questions, answered directly

Common questions from process plant procurement teams, EPC project buyers, and tube fabrication shops.

What's the difference between centrifugal cast tubes and seamless tubes?

Seamless tubes are made by hot-piercing a solid billet and rolling — economical for smaller diameters (under 200 mm OD) and standard alloys. Centrifugal casting is the standard route for larger diameters (100-1,800 mm OD), heat-resistant alloys (HP40, HK40, Inconel), wear-resistant alloys (high-Cr), and tubes longer than economical seamless production. Centrifugal castings have denser grain structure in the outer wall, fewer porosity defects than static castings, and better OD surface finish than fabricated alternatives.

What OD range can you centrifugally cast?

100 mm to 1,800 mm OD on our horizontal line, 200 mm to 1,500 mm OD on our vertical line. Below 100 mm, seamless tube is typically more economical. Above 1,800 mm, projects require custom mold tooling and quotation on a project-by-project basis. We have completed special projects up to 2,200 mm OD with custom mold preparation.

What's the maximum tube length you can cast as a single piece?

6,000 mm (6 meters) for most standard stainless and alloy tubes on our horizontal line. For HP-Nb reformer tubes with smaller OD, we can cast up to 14 meters single-piece. Longer tube assemblies are joined by tube-to-tube welding with matching alloy filler — we can perform welding in-house or ship as separate pieces for site welding.

Can you do pressure testing for tube castings?

Yes. Hydrostatic pressure testing per ASME B31.3 or buyer specification is standard for pressure-service tubes. Standard test pressure is 1.5x design pressure, held for the duration specified by the applicable standard. Test certificates issued per tube with serial number. Pneumatic testing also available for low-pressure applications where hydrostatic testing isn't practical.

What surface finish can you achieve?

As-cast OD: Ra 6.3-12.5 μm (250-500 μin). After OD machining: Ra 1.6-3.2 μm (63-125 μin) standard. ID after rough machining (to remove impurity layer): Ra 3.2-6.3 μm. Tighter finishes (below Ra 0.8 μm mirror polish) available for specific applications but adds significant cost — rarely needed for industrial pipe service.

What's the typical lead time for centrifugal cast tubes?

Standard catalog tubes (stainless, HK40, basic HP40): 25-35 days from confirmed PO. Custom-spec tubes with new mold tooling: 40-60 days. Large bore (above 1,200 mm OD) or heavy castings (above 5,000 kg per piece): 50-75 days. Heat treatment and NDT testing included in lead time. PED certification path: add 10-15 days.

Can you cast tubes with flanges as one piece?

Yes. Flanged tubes are one of our specialty products. Single-piece centrifugal casting eliminates the flange-to-pipe weld joint that's a common failure point in fabricated alternatives. Flange face is finish-machined to ANSI B16.5 or DIN standards. Available with raised face, flat face, or ring-type joint configurations.

What alloy families do you cast?

Seven major families: stainless steel (304H, 316L, 310, 321H), HP series (HP40, HP-Nb, HP-Mod), HK series (HK40, HK45), nickel alloys (Inconel 600/625/800H, Incoloy), heat-resistant (1.4848, 1.4865, 35Cr-45Ni), wear-resistant (high-Cr cast iron, Ni-Hard), and copper/bronze (aluminum bronze, leaded bronze). Custom buyer-spec chemistry also produced per project drawing.

What's the MOQ for centrifugal cast tubes?

No fixed piece-count MOQ. Standard sizes from our existing mold library ship from 1 piece. For new mold tooling (non-standard OD/ID), the project becomes economical at 5-10 tubes of the same geometry. Standard alloy tubes (304H, 316L, HK40) are typically available faster than specialty alloys (Inconel, custom HP-Nb).

Do you ship tubes worldwide?

Yes. Active centrifugal cast tube shipments to 40+ countries — US, UK, Germany, France, Italy, Russia, South Korea, Japan, Canada, Pakistan, Kazakhstan, Taiwan, Saudi Arabia, UAE, Thailand, Indonesia. FOB Qingdao standard quote; CIF, DDP, and project-specific freight handled through partnered forwarders. Tubes packed with ID end caps and OD plastic wrap to prevent transit damage.