AISI 4130 Flanges | UNS G41300 | DIN 1.7218

AISI 4130 flanges, also called SAE 4130 or UNS G41300, are forged from a chromium-molybdenum low-alloy steel that gives you a strong balance of strength, toughness, and weldability. This medium-carbon alloy runs roughly 0.28-0.33% carbon, 0.80-1.10% chromium, 0.15-0.25% molybdenum, and 0.40-0.60% manganese, which lift its hardenability, fatigue resistance, and overall mechanical performance. We produce AISI 4130 flanges to standards such as ASME B16.5, in weld neck, slip-on, blind, socket weld, threaded, and spectacle blind types, so they cover a wide spread of piping connections. PM Industries manufactures, supplies, and stocks them in a full range of types, sizes, and classes.

In the normalized or quenched-and-tempered condition, 4130 shows tensile strength around 560 MPa, yield near 460 MPa, and good elongation of about 21.5%. That ductility and impact resistance make it a strong pick for cyclic loading and moderate temperatures. The chromium gives it better atmospheric corrosion resistance than plain carbon steel, though coatings are still a good idea in harsher settings. The alloy welds readily with common processes, as long as you use proper preheat and post-weld heat treatment to keep its properties intact.

You will find AISI 4130 flanges across oil and gas, aerospace, automotive, and petrochemical work. They suit high-pressure piping, wellhead equipment, drilling components, aircraft structural parts, and general engineering, anywhere lightweight strength and reliability count. They perform well in pressure classes from 150 to 2500, handle moderate to high-stress service, and machine cleanly for precise fabrication.

A big draw of 4130 is its through-hardening and high strength-to-weight ratio, which lets designers cut material thickness without losing performance. That makes it a favorite for mobile equipment, racing components, and structural frameworks. We supply the flanges with full material traceability, heat-treatment certificates, and compliance to international quality standards for safety-critical service. The alloy also works cold and hot forms well, which adds to its fabrication flexibility.

AISI 4130 flanges stay a go-to for engineers who want cost-effective, high-performance parts in demanding conditions. Their track record in aerospace tubing, pressure vessels, and transmission systems speaks to their durability. Chosen, installed, and maintained properly, they deliver long service life. 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 4130 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 Grades Of AISI 4130 Forged Flanges

STANDARD	WERKSTOFF NR.	UNS	JIS	BS	EN
AISI 4130	1.7218	G41300	JIS G4105	BS 970	25CrMo4

hysical properties of alloy 4130 Lap Joint Flanges

Properties	Metric	Imperial
Density	7.85 g/cm3	0.284 lb/in³
Melting point	1432°C	2610°F

Alloy Steel AISI 4130 Forged Flanges Thermal Properties

Properties	Metric	Imperial
Thermal conductivity (100°C)	42.7 W/mK	296 BTU in/hr.ft2. °F

SAE 4130 Flange Chemical Composition Chart

Grade	Carbon	Manganese	Silicon	Phosphorus	Sulfur	Iron	Molybdenum	Nickel	Chromium
AISI 4130	0.28-0.33	0.40-0.60	0.15-0.35	0.035 maximum	0.025 maximum	97.3-98.22	0.15-0.25	0.50 maximum	0.80-1.10

Mechanical Strength of Alloy Steel Aisi 4130 Flanges

Density	Elongation	Melting Point	Tensile Strength	Yield Strength
7.85 g/cm3	21.50%	1432 ℃	560	460

Pressure rating of Alloy Steel 4130 60k Blind Flanges

Max. Working Pressure	2,000 PSI	3,000 PSI	5,000 PSI	10,000 PSI	15,000 PSI	20,000 PSI
Test Pressure	3,000 PSI	4,500 PSI	7,500 PSI	15,000 PSI	22,500 PSI	30,000 PSI
Product Specification Levels	1, 2, 3 & 4	1, 2, 3 & 4	1, 2, 3 & 4	1, 2, 3 & 4	1, 2, 3 & 4	1, 2, 3 & 4
API Temperature Rating	K (-60 Deg C)	K (-60 Deg C)	K (-60 Deg C)	K (-60 Deg C)	K (-60 Deg C)	K (-60 Deg C)
	To	To	To	To	To	To
	Y (+345 Deg C)	Y (+345 Deg C)	Y (+345 Deg C)	Y (+345 Deg C)	Y (+345 Deg C)	Y (+345 Deg C)

Chromoly 4130 Plate 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

Dimension of AISI 4130 Weld Neck Flanges

NPS	Flanges ID (inch)	Flanges OD (inches)
		Alloy Steel Class 150	Alloy Steel Class 300	Alloy Steel Class 400	Alloy Steel Class 600	Alloy Steel Class 900
1/2	0.84	1.875	2.125	2.125	2.125	2.50
3/4	1.06	2.25	2.625	2.625	2.625	2.75
1	1.31	2.625	2.875	2.875	2.875	3.125
1 1/4	1.66	3	3.25	3.25	3.25	3.50
1 1/2	1.91	3.375	3.75	3.75	3.75	3.875
2	2.38	4.125	4.375	4.375	4.375	5.625
2 1/2	2.88	4.875	5.125	5.125	5.125	6.50
3	3.50	5.375	5.875	5.875	5.875	6.625
4	4.50	6.875	7.125	7.00	7.625	8.125
5	5.56	7.75	8.50	8.375	9.50	9.75
6	6.62	8.75	9.875	9.75	10.50	11.375
8	8.62	11	12.125	12.00	12.625	14.125
10	10.75	13.375	14.25	14.125	15.75	17.125
12	12.75	16.125	16.625	16.50	18.00	19.625