ASTM A815 CR429
ASTM A815 CR429 Wrought Ferritic Stainless Steel Pipe Fittings
ASTM A815 CR429 refers to wrought ferritic stainless steel pipe fittings manufactured in accordance with ASTM A815 / A815M standards. The CR class signifies fittings produced to MSS SP-43 requirements and suitable for corrosive and moderate-temperature environments.
These fittings are made from UNS S42900 (Type 429) stainless steel — a ferritic stainless alloy containing approx. 14.0–18.0% chromium, offering excellent corrosion resistance, scale resistance, and dimensional stability. CR429 fittings are ideal for industries demanding durable, corrosion-resistant piping solutions at an economical cost compared to austenitic alloys.
Key Features
Manufactured from UNS S42900 ferritic stainless steel
Good oxidation & scaling resistance at elevated temperatures
Enhanced chloride-related corrosion resistance
Excellent resistance to stress corrosion cracking
Economical alternative to 304/316 stainless grades in many environments
Stable structure with low carbon for weldability & formability
Good performance in mild acids, alkalis & atmospheric conditions
Specification
| Property | Detail |
|---|---|
| Standard | ASTM A815 / A815M |
| Grade | CR429 |
| Material Type | Ferritic Stainless Steel |
| UNS | S42900 |
| Equivalent | Type 429 Stainless Steel |
| Class | CR (to MSS SP-43) |
| Form | Wrought Welded Pipe Fittings |
| Size Range | ½” to 48” (DN15 to DN1200) |
| Thickness Range | SCH 10 – SCH XXS |
| End Connection | Bevelled for Butt-Weld |
| Surface | Mill Finish / Pickled & Passivated |
Equivalent Grades
| Standard | Grade |
|---|---|
| UNS | S42900 |
| AISI | 429 |
| ASTM | A815 CR429 |
| EN | Comparable to 1.4016 / Similar ferritic grade |
| JIS | Equivalent ferritic stainless reference |
Note: Type 429 is a ferritic stainless steel similar to Type 430 with better heat resistance.
Available Sizes
Outside Diameter: ½” to 48”
Thickness: SCH 10, SCH 40, SCH 80, SCH 160, XXS
Available in Elbows, Tees, Reducers, Caps, Stub Ends
Chemical Composition
| Element | Content (%) |
|---|---|
| Chromium (Cr) | 14.0 – 18.0 |
| Carbon (C) | ≤ 0.12 |
| Manganese (Mn) | ≤ 1.0 |
| Silicon (Si) | ≤ 1.0 |
| Nickel (Ni) | ≤ 0.5 |
| Phosphorus (P) | ≤ 0.040 |
| Sulfur (S) | ≤ 0.030 |
| Iron (Fe) | Balance |
Mechanical Properties
| Property | Value |
|---|---|
| Tensile Strength | ≥ 415 MPa |
| Yield Strength | ≥ 275 MPa |
| Elongation | ≥ 20% |
Physical Properties
| Property | Value |
|---|---|
| Density | 7.7 – 7.8 g/cm³ |
| Melting Point | 1420°C – 1510°C |
| Modulus of Elasticity | ~200 GPa |
| Thermal Conductivity | Higher than 300-series stainless |
| Expansion Coefficient | Lower than austenitic stainless steel |
Types of ASTM A815 CR429 Fittings
ASTM A815 CR429 Elbow
ASTM A815 CR429 Tee
ASTM A815 CR429 Reducers
ASTM A815 CR429 Caps
ASTM A815 CR429 Cross Fittings
ASTM A815 CR429 Nipples
ASTM A815 CR429 Couplings
ASTM A815 CR429 Stub Ends
Corrosion Resistance
Strong resistance to atmospheric & freshwater corrosion
Good resistance to mild acids, alkali & organics
Better chloride pitting resistance than 400-series stainless
Superior stress-corrosion cracking resistance vs austenitic steels
Heat Resistance
Good oxidation resistance up to ~800–850°C
Suitable for heat exchangers, heaters, exhaust systems
Excellent scaling resistance in intermittent high temperatures
Heat Treatment
Annealing: 780°C – 900°C, followed by air cooling
Stress-relief heat treatment may enhance service performance
Avoid rapid quenching to prevent brittleness
Welding
Suitable for standard ferritic stainless steel welding processes
Recommended filler: matching stainless grade
Pre-heat: not generally needed
Post-weld annealing beneficial for critical applications
Fabrication
Good machinability & formability
Avoid excessive cold forming without intermediate heating
Can be cut, formed, and welded with conventional methods
Applications
Chemical Processing Equipment
Food & Dairy Piping (non-chloride environments)
Heat-resistant Ducts & Exhaust Systems
Power Plant & Boiler Components
Industrial Heat Exchangers
Water Treatment & Filtration Systems
Architectural & Structural Piping
Automotive & Industrial Muffler Systems