🟦 Product Overview

ASTM A335 (ASME SA335) is the world’s most widely used high‑temperature, high‑pressure alloy steel pipe standard, commonly known as Chrome‑Moly Pipe.

It is engineered for:

• High‑temperature service
• High‑pressure steam systems
• Power plant piping
• Petrochemical & refinery pipelines
• Boiler & superheater systems

The alloying elements Cr (Chromium) and Mo (Molybdenum) provide:

• Excellent high‑temperature strength
• Superior creep resistance
• Enhanced oxidation & corrosion resistance
• Long‑term stability under thermal cycling

A335 includes multiple grades, each designed for specific temperature and pressure conditions.

🟦 A335 Grade Overview

P1 — Low Alloy, General High‑Temp Service

• 0.5% Mo
• Good for moderate temperatures
• Cost‑effective option

P5 — 5% Cr, 0.5% Mo

• Excellent oxidation resistance
• Used in refinery & petrochemical heaters

P9 — 9% Cr, 1% Mo

• Higher strength than P5
• Suitable for high‑pressure steam lines

P11 — 1.25% Cr, 0.5% Mo

• Most widely used grade
• Ideal for power plants & boilers

P22 — 2.25% Cr, 1% Mo

• Higher creep resistance
• Standard for high‑temperature steam systems

P91 — 9% Cr, 1% Mo + V/Nb

• Ultra‑high strength
• Designed for ultra‑supercritical power plants
• Excellent creep & thermal fatigue resistance

🟦 Standards

• ASTM A335 / ASME SA335
• ASTM A999 (General Requirements)
• EN 10216‑2 (Equivalent)
• GB/T 5310 (Equivalent for boiler tubes)

🟦 Product Specifications & Available Sizes

Outer Diameter (OD)

• 10–1200 mm

Wall Thickness (WT)

• 1.5–100 mm

Length

• 6 m / 12 m / SRL / DRL / custom

Manufacturing Methods

• Hot Rolled Seamless
• Cold Drawn Seamless
• Normalized / Tempered
• Quenched & Tempered (P91)

End Types

• Plain End
• Beveled End

Diameter * wall thickness (mm)
14×3	60×6	168×9.5	325×20
14×3.5	60×7	168×10	325×22
14×4	60×8	168×11	325×23
16×3	60×9	168×12	325×25
18×2	60×10	168×14	325×28
18×3	76×4.5	168×15	325×30
18×4	76×5	168×16	325×32
18×5	76×6	168×18	325×36
19×2	76×7	168×20	325×40
21×4	76×8	168×22	325×45
22×2.5	76×9	168×25	356×9.5
22×3	76×10	168×28	356×12
22×4	89×4	180×10	356×15
22×5	89×4.5	194×10	356×19
25×2.5	89×5	194×12	356×28
25×3	89×5.5	194×14	356×36
25×4	89×6	194×16	377×9
25×5	89×7	194×18	377×10
25×5.5	89×7.5	194×20	377×12
27×3.5	89×8	194×26	377×14
27×4	89×9	219×6.5	377×15
27×5	89×10	219×7	377×16
27×5.5	89×11	219×8	377×18
28×5.5	89×12	219×9	377×20
28×3	108×4.5	219×10	377×22
28×3.5	108×5	219×12	377×25
28×4	108×6	219×13	377×32
30×2.5	108×7	219×14	377×36
32×2.5	108×8	219×16	377×40
32×3	108×9	219×18	377×45
32×3.5	108×10	219×20	377×50
32×4	108×12	219×22	406×9.5
32×4.5	108×14	219×24	406×11
32×5	108×15	219×25	406×13
34×3	108×16	219×26	406×17
34×4	108×20	219×28	406×22

🟦 Chemical Composition (Typical)

P11

Element	Content (%)
C	0.05–0.15
Mn	0.30–0.60
Si	0.50–1.00
Cr	1.00–1.50
Mo	0.44–0.65

P22

Element	Content (%)
C	0.05–0.15
Mn	0.30–0.60
Si	0.50–1.00
Cr	2.00–2.50
Mo	0.87–1.13

P91

Element	Content (%)
C	0.08–0.12
Mn	0.30–0.60
Cr	8.00–9.50
Mo	0.85–1.05
V	0.18–0.25
Nb	0.06–0.10

🟦 Mechanical Properties

P11

Property	Requirement
Tensile Strength	≥ 415 MPa
Yield Strength	≥ 205 MPa

P22

Property	Requirement
Tensile Strength	≥ 415 MPa
Yield Strength	≥ 205 MPa

P91

Property	Requirement
Tensile Strength	≥ 585 MPa
Yield Strength	≥ 415 MPa

🟦 Physical Properties

Property	Value
Density	7.85 g/cm³
Melting Point	~1425–1510°C
Thermal Conductivity	24–35 W/m·K
Magnetic	Yes

🟦 Manufacturing Processes

• Hot Rolling
• Cold Drawing
• Normalizing
• Tempering
• Quenching (P91)
• Hydrostatic Testing
• Eddy Current Testing
• Ultrasonic Testing

🟦 Primary Industry Usage

• Power plant piping
• High‑pressure steam lines
• Petrochemical heaters
• Refinery piping
• Boiler & superheater systems
• Heat exchangers
• Industrial high‑temperature pipelines

🟦 Why Use ASTM A335 Alloy Steel Pipe

• Designed for high temperature + high pressure
• Excellent creep & oxidation resistance
• Long‑term stability under thermal cycling
• Multiple grades for different temperature ranges
• Global standard for power & petrochemical industries

🟦 Why Choose WelSteels

• Full range of P1 / P5 / P9 / P11 / P22 / P91
• Heat treatment capability (N+T, Q+T)
• MTC 3.1 + third‑party inspection
• Export‑grade packaging & loading supervision
• Competitive pricing for power & refinery projects

International Steel Pipe Standards

China	America	Germany	Japan	France	Britain	International
GB3077	AlSI	DIN	JIS	NE	BS	ISO
20Mn2	13201221	20Mn5	SMn21	20M5	150M19	–
30Mn2	1330	30Mn5	SMn24	32M5	150M28	–
35Mn2	1335	36Mn5	SMnl	35M5	150M36	–
40Mn2	13401341	–	SMn2	40M5	–	–
45Mn2	1345	46Mn7	SMn3	45M5	–	–
50Mn2	1052	50Mn7	–	55M5	–	–
20MnV	–	20MnV6	–		–	–
30Mn2MoW	–	—	–		–	–
27SiMn	–	27MnSi5	–		–	–
35SiMn	–	37MnSi5	–	38MS5	–	–
42SiMn	–	38MnSi446MnSi4	–	38MS5	–	–
20SiMn2MoV	–	–	–	–	–	–
25SiMn2MoV	–	–	–	–	–	–
37SiMn2MoV	–	–	–	–	–	–
40B	14B35	35B2	–	–	–	–
45B	50B46H	45B2	–	–	–	–
50B	14B50	–	–	–	–	–
4OM∏B	15B41	–	–	–	–	–
45MnB	15B4850B44	–	–	–	–	–
20Mn2B	–	–	–	–	–	–
20MnMoB	80B20	–	–	–	–	–
15MnVB	–	–	–	–	–	–
–	–	–	–	–	–	–
–	–	–	–	–	–	–
20MnVB	–	–	–	–	–	–
40MnVB	–	–	–	–	–	–
20MnTiB	–	–	–	–	–	–
25MnTiBRE	–	–	–	–	–	–
2OSiMnVB	–	–	–	–	–	–
15Cr	50155115	15Cr3	SCr21	12C3	523A14523M15	–
15CrA	–	–	–	–	–	–
20Cr	5120	20Cr4	SCr22	18C318C4	527A19527M20	683/1120Cr420CrS4
30Cr	5130	28Cr4	SCr2	28C432C4	530A30530A32	–
35Cr	5135	34Cr437Cr4	SCr3	38C4	530A36	683/83、 3a、 3b
40Cr	5140	38Cr441Cr4	SCr4	42C4	530A40530M40	683/14、 4a^ 4b
45Cr	5145	42Cr4	SCR5	45C4	–	–
50Cr	51505152	–	–	50C4	En48	–
38CrSi	–	–	–	–	–	–
12CrMo	4119	13CrMo44	–	12CD415CD2	–	–
15CrMo	ASTMA-387Gr. B	15CrMo516CrMo44	SCM21	15CD4. 05	BS1653	–
20CrMo	4118	20CrMo522CrMo4	SCM22	18CD420CD4	CDS 12CDSllO	–
30CrMo	4130	25CrMo4	SCM2	30CD4	CDS 13	–
30CrMoA	–	32CrMol23ICRMo12	–	–	–	–
35CrMo	41354137	34CrMo435CrMo4	SCM3	35CD4	78A37	683/1C35eaC35eb
42CrMo	41404142	41CrMo442CrMo4	SCM4	40CD442CD4	708M40708A42709M40	683/13
12CrMoV	–	–	–	–	–	–
35CrMoV	–	35CrMoV5	–	–	–	–
12CrlMoV	–	13CrMoV4.2	–	–	–	–
25Cr2MoVA	–	24CrMoV5.5	–	–	–	–
25Cr2MolVA	–	–	–	–	–	–
20CR3MoWVA	–	21CrVMoW12	–	–	–	–
38CrMoΛl	6370 (ΛMS)	34CrAlMo541CrAlMo7	SACM645	40CAD6.12	905M39	683/1041CrAlMo74
20CrV	6120	22CrV4	–	22CrV4	–	–
40CrV	6140	42CrV	–	42CrV4	–	–
50CrVA	6150	50CrV4	SUPlO	50CV4	735A50	–
15CrMn	–	16MnCr5	–	16MC5	–	–
20CrMn	5120	20MnCr5	SMC21	20MC5	–	–
40CrMn	5140	–	SMC3	–	–	–
20CrMnSi	–	–		–	–	–
25CrMnSi	–	–	SMKl	–	–	–
30CrMnSi	–	–	–	–	–	–
30CrMnSiA	–	–	–	–	–	–
35CrMnSiA	–	–	SMK2	–	–	–
20CrMnMo	4119	20CrMo5	SCM23	–	–	–
40CrMnMo	4140	–	–	–	–	–
20CrMnTi	–	–	SMK22	–	–	–
30CrMnTi	–	30MnCrTi4	–	–	–	–
20CrNi	3120	20NiCr6	–	20NC6	637A16637M17	–
40CrNi	3140	46NiCr6	SNCl	35NC6	640A35640M40	–
45CrNi	3145	45NiCr6	–	–	–	–
50CrNi	3150	–	–	–	–	–
12CrNi2	3115	14NiCrlO	SNC21	IONCll14NC11	–	–
12CrNi3	3310	13NiCrl2	SNC22	10NC1214NC12	655A12655M13	–
20CrNi3	–	22NiCrl4	–	20NC11	–	–
30CrNi3	–	28NiCrlO31NiCrl4	SNC2	30NC1130NC12	–	–
37CrNi3	–	35NiCrl8	SNC3	35NC15	–	–
12Cr2Ni4	E3310	14NiCrl8	–	12NC15	–	–
20Cr2Ni4	E3316	22NiCrl4	–	20NC14	659A15659M15	–
20CrNiMo	8620    8720	20NiCrMo221NiCrMo2	–	20NCD2	805A20805M20	–
40CrNiMoA	4340     9840	36NiCrMo440NiCrMo6	SNCM8	35NCD540NCD3	817M40816M40	–
45CrNiMoVA	4437	–	SNCM9	–	–	–
18Cr2Ni4WA
25Cr2Ni4WA