AISI 4140 Flanges | UNS G41400 | DIN 1.7225

AISI 4140 flanges, also called SAE 4140 or UNS G41400, are made from a chromium-molybdenum low-alloy steel known for strength, toughness, and wear resistance. This medium-carbon alloy runs roughly 0.38-0.43% carbon, 0.75-1.0% manganese, 0.80-1.10% chromium, and 0.15-0.25% molybdenum. That mix gives it good hardenability and the ability to reach high mechanical properties through heat treatment such as quenching and tempering. We produce AISI 4140 flanges to standards like ASME B16.5, in weld neck, slip-on, blind, socket weld, and threaded forms for critical piping connections. PM Industries manufactures, supplies, and stocks them in a full range of types, sizes, and classes.

The material performs well mechanically, with minimum tensile strength around 655 MPa and yield near 415 MPa in the normalized or quenched-and-tempered condition. It brings high fatigue resistance, good impact toughness, and excellent abrasion resistance, which suits high-stress service. It is not as corrosion-resistant as stainless steel, but it holds up in moderate atmospheric conditions and can be coated for protection or run in oil, gas, and non-corrosive fluid service. Good machinability and weldability, with proper preheat, keep both shop fabrication and field installation straightforward.

You will find AISI 4140 flanges in oil and gas, petrochemical, power generation, mining, and heavy machinery. They earn their place connecting valves, pumps, and pipelines that handle high-pressure hydrocarbons, steam, or drilling fluids, where high tensile strength and resistance to deformation matter. Pressure ratings usually align with Class 150 through 2500, depending on design, temperature, and heat treatment, and they hold reliable sealing and structural integrity up to about 315°C (600°F) in sustained service.

Engineers pick 4140 when they want a step up from standard carbon steel without paying for more exotic grades. The deep-hardening behavior keeps properties uniform even in thicker sections, which lowers the risk of failure under cyclic load or high pressure. We supply the flanges in raised face, flat face, and ring-type joint facings to match your gasket and service, each with full traceability, material test certificates, and compliance to international specifications.

For demanding industrial piping, AISI 4140 flanges give a strong balance of strength, toughness, and value. Proper heat treatment and sound installation practice get the most service life out of them. PM Industries holds stock ready to ship, with certification and test documentation on every order. Tell us your flange type, size, class, and face, and we will quote it.

Specification AISI 4140 Flanges

Standards	ANSI/ASME B16.5, B16.48, ANSI Flanges, GOST Flanges, DIN Flanges, EN-1092, B16.47 Series A & B, ASME Flanges, EN Flanges, AWWA Flanges, BS Flanges.
JIS Standard	5K, 10 K, 16 K 20 K, 30 K, 40 K, 63 K
DIN FLANGES	DIN 2527, 2627, 2631, 2656, 2576, 2673, 2629, 2628, 2566, 2641, 2637, 2655, 2634, 2636, 2632, 2633, 2638, 2642, 2573, 2635.
Pressure Rating	Class 150 LBS, 300 LBS, 600 LBS, 900 LBS, 1500 LBS, 2500 LBS
Types	Threaded, Plate, Screwed, Forged.
Supporting material	Gasket, Ring Joint, Flange Bolts
Size range	1/2" (15 NB) to 48" (1200NB) DN10~DN5000
Production technique	Forged, machined and Heat treated
Available Flange Type	Weld Neck Flanges, RTJ Flanges, Slip On Flanges, Spectacle Blind Flanges, Flanges Gaskets, Square Flanges, Standard Insert Flanges, High Hub Blinds Flanges, Flat Flanges, forged flanges, Weldo / Nipo Flanges, Jacket Insert Flanges, Tongue groove Flanges, Blind Flanges, Socket Weld Flanges, Large diameter Flanges, Long Weld Neck Flanges, Spacer Blinds, SWRF Flanges, SORF Flanges, Angle Face Rings Flanges, Spades Ring Spacers Flanges, WNRF Flanges, Screwed Flanges, Insert Flanges, flanges bolts, cf flange, Lap Joint Flanges, ASME B16.36 Orifice Flanges, Plate Flange, Expander Flanges, Ring Type Joint Flanges, Loose Flanges, Reducing Flanges, puddle flange, Threaded Flanges, blank flange, vacuum flange.
Connect Type/ Flange Face Type	Ring Type Joint (RTJ), Flat Face (FF), Tongue & Groove, Small Male-Female (SMF), Lap-Joint Face (LJF), Raised Face (RF), Large Male-Female (LMF), Small Tongue.
Custom design	As per your drawing
Test	Direct-reading Spectrograph, X-ray detector, UItrasonic flaw detector, Magnetic particle detector, Hydrostatic testing machine.
Origin	Indian / USA / Korean / West Europe / Japan
Pressure Class	PN 6 TO PN 100
Thickness	Normal Pipe Size ≤ 18
Bore Diameter	Normal Pipe ≤ 10
High Temperature	Above 200°C (400°F) For Class 150 Or Above 400°C (750°F)
Low Temperature	Above -29 Degree C (−20°F)
Coating/Surface Treatment:	Zinc Plated, Anti-rust Paint, Oil Black Paint, Yellow Transparent, Cold and Hot Dip Galvanized.
European/African/Russian Standard Flanges	Available
Gaskets Types	Full Face, Metallic Ring, Flat Ring Gasket
Marking Standard	Name of Manufacturer
	Schedule
	Type of Flange Facing
	Pressure Class
	Nominal Pipe Size, etc
Test Certificates	EN 10204/3.1B, NACE MR0103, NACE MR0175
	Raw Materials Certificate
	100% Radiography Test Report
	Third Party Inspection Report, etc

Flange Type Available

Equivalent Grade

STANDARD	UNS	WERKSTOFF NR.
AISI 4140	G41400	1.7225

Chemical Properties

Element	Content
Chromium	0.80 Tp 1.10
Manganese	0.75 Tp 1.0
Silicon	0.15 To 0.30
Carbon	0.380 To 0.430
Molybdenum	0.15 To 0.25
Sulfur	0.040
Phosphorous	0.035
Iron	Balance

AISI 4140 Pipe Flanges Weight Chart

Nominal Pipe Size		Dimension		Weight in Kg
Normal Pipe Size (Inche)	Diameter Nominal	Flange Outer Diameter in MM	Flange Thickness in MM	Socket Weld	Weld Neck	Blind
8	200	342.9	28.4	12.1	17.6	19.6
3/4	20	98.6	12.7	0.6	0.7	0.6
1	25	108	14.2	0.8	1	0.9
1 1/4	32	117.3	15.7	1	1.3	1.2
1 1/2	40	127	17.5	1.3	1.7	1.5
2	50	152.4	19.1	2.1	2.6	2.4
2 1/2	65	177.8	22.4	3.3	4.1	3.9
1/2	15	88.9	11.2	0.4	0.5	0.4
3	80	190.5	23.9	3.9	4.9	4.9
24	600	812.8	47.8	86.9	115	185.0
3 1/2	90	215.9	23.9	4.8	6.1	6.2
4	100	228.6	23.9	5.3	6.8	7.0
5	125	254	23.9	6.1	8.6	8.6
6	150	279.4	25.4	7.5	10.6	11.3
10	250	406.4	30.2	16.5	24	28.6
14	350	533.4	35.1	34.6	48.4	58.1
12	300	482.6	31.8	26.2	36.5	43.2
16	400	596.9	36.6	44.8	60.6	76.1
18	450	635	39.6	48.9	68.3	93.7
20	500	698.5	42.9	61.9	84.5	122.0

UNS G41400 Flange Mechanical Properties

Properties	Metric	Imperial
Tensile strength	655 MPa	95000 psi
Bulk modulus	140 GPa	20300 ksi
Yield strength	415 MPa	60200 psi
Shear modulus	80 GPa	11600 ksi
Poisson's ratio	0.27-0.30	0.27-0.30
Elastic modulus	190-210 GPa	27557-30458 ksi
Elongation at break (in 50 mm)	25.70%	25.70%
Hardness, Knoop	219	219
Hardness, Rockwell B	92	92
Hardness, Brinell	197	197
Hardness, Rockwell C	13	13
Machinability	65	65
Hardness, Vickers	207	207