Alloy Steel 8630 Round Bar
➡️ AISI 8630 | UNS G86300 | EN 1.6545
➡️ ASTM, EN, JIS & International Standards
➡️ Supply Conditions
➡️ Multiple Diameters & Supply Lengths
➡️ Global Export & International Delivery
Country of Origin:
Europe, Japan, USA
Material Type:
Alloy Steel
UNS Number:
G86300
Wr. No.:
1.6545
MTC Available:
EN 10204 3.1
Product Description for Alloy Steel 8630 Round Bar
Alloy Steel 8630 Round Bar is a solid cylindrical bar produced from low-alloy nickel-chromium-molybdenum steel grade AISI/SAE 8630 (UNS G86300). Bar is supplied to ASTM A29 / A29M for general requirements and to ASTM A322 for hot-wrought alloy steel bars, with cold-finished bar covered by ASTM A108. Forged bar and components for oilfield service are frequently ordered to ASTM A29 with supplementary requirements or to customer specifications such as API 6A material class ratings.
The grade contains approximately 0.30% carbon with a balanced addition of about 0.55% nickel, 0.50% chromium and 0.20% molybdenum. This triple alloying gives markedly better hardenability than plain carbon steel, allowing sections up to about 100 mm to be through-hardened with an oil quench, while the moderate carbon level keeps weldability workable and toughness high. After quenching and tempering, tensile strengths of 850-1000 MPa are typical with good impact energy, and the grade is regularly qualified to low-temperature Charpy requirements.
Bars are supplied hot-rolled, normalised, annealed, or quenched and tempered, in diameters from about 15 mm to 500 mm and lengths of 3 to 6 m. Machinability in the annealed condition is good, and the steel can be flame or induction hardened.
Typical applications include wellhead and subsea components, valve bodies and bonnets, connectors, hangers, gears, shafts, axle components, crankshafts, fasteners, forged fittings and structural weldments. Industries served include oil and gas, subsea equipment, automotive and heavy vehicle manufacture, mining, power transmission and general heavy engineering.
Common Applications of Alloy Steel 8630 Round Bar
➡️ Machined shafts, spindles, valve stems, pump sleeves and pins for food, beverage, dairy and pharmaceutical equipment, where the passive chromium oxide film resists both product acids and caustic clean-in-place chemicals.
➡️ Fasteners, studs, bolts, threaded rod and anchor components produced from bar stock, chosen for corrosion resistance combined with the ductility needed for cold heading and thread rolling.
➡️ Chemical, water treatment and general process plant parts such as agitator shafts, flange blanks, nozzles and support components handling water, steam and mildly corrosive media free of significant chlorides.
➡️ Architectural and structural hardware including handrail stanchions, balustrade fittings, tension rods and bollards, where a bright ground or polished bar finish provides both appearance and low maintenance.
International Equivalent Grade for AS 8630 Round Bar
Standard
Country / Region
Grade
ASTM A29 / A29M
USA
Grade 8630 (UNS G86300)
ASTM A322
USA
Grade 8630 - hot-wrought alloy steel bar
ASTM A108
USA
Grade 8630 - cold-finished bar
SAE J404
USA
8630
EN 10083-3
Europe / EU
30NiCrMo2-2 (1.6545) - nearest equivalent
BS EN 10083-3
United Kingdom
30NiCrMo2-2 (1.6545) - nearest equivalent
ISO 683-2
International
30NiCrMo2-2 - nearest equivalent
Technical Specification for Alloy Steel 8630 Round Bar
Specification
Value
Unit
Material
Alloy steel
-
Grade
8630 / UNS G86300
-
Product Form
Round bar / rod / forged bar
-
Standard
ASTM A29 / A29M and ASTM A322
-
Diameter
15 - 500 (available range)
mm
Length
3 - 6 (standard random or fixed)
m
Manufacturing Process
Hot rolled, forged, or hot rolled and cold drawn
-
Production Route
EAF melting with ladle refining, continuous cast or ingot, hot rolling or forging, heat treatment
-
Surface Finish
Hot-rolled black, peeled, rough turned, cold-drawn bright, turned ground and polished
-
Heat Treatment / Delivery Condition
As-rolled, annealed, normalised, or quenched and tempered as ordered
-
Normalising Temperature
870 - 900 then air cool (typical)
deg C
Annealing Temperature
810 - 850 then furnace cool (typical)
deg C
Hardening Temperature
845 - 870 followed by oil quench (typical)
deg C
Tempering Temperature
540 - 660 depending on required strength (typical)
deg C
Tolerance Standard
ASTM A29 / A29M and ASTM A108
-
Carbon Equivalent (CEV)
0.65 (typical, IIW formula)
-
Density
7.85 (typical)
g/cm3
Melting Point
1500 (approximate)
deg C
Thermal Conductivity
42.0 at 100 deg C (typical)
W/m.K
Coefficient of Thermal Expansion
12.3 at 20 - 100 deg C (typical)
micro-m/m.K
Specific Heat
477 at 50 - 100 deg C (typical)
J/kg.K
Electrical Resistivity
0.225 (typical)
micro-ohm.m
Modulus of Elasticity
205 (typical)
GPa
Magnetic Properties
Ferromagnetic
-
Applicable Testing Standard
ASTM A370, ASTM E8 / E8M, ASTM E23, ASTM E10, ASTM E415
-
Certification / Inspection Documents
EN 10204 Type 3.1 or 3.2 mill test certificate
-
Technical Specifications
Get the key technical specifications for Alloy Steel 8630 Round Bar
Alloy Steel 8630 Round Bar is ordered to ASTM A29 / A29M for general requirements and ASTM A322 for hot-wrought alloy steel bars, with ASTM A108 applying to cold-finished product. These standards define chemical composition, dimensional tolerance and quality requirements. They do not impose mechanical property minima for 8630 as a default, so strength and impact requirements must be stated by the purchaser, typically as a quench and temper condition with a specified tensile range and Charpy requirement.
Hardening is performed from about 845-870 deg C with an oil quench. The nickel, chromium and molybdenum additions slow the transformation to ferrite and pearlite, so a martensitic structure is obtained to considerable depth and sections up to roughly 100 mm can be through-hardened. Tempering between 540 and 660 deg C sets the final strength.
In oilfield service the grade is very common as a forged product for wellhead and subsea equipment, where API 6A material class requirements govern. Grade 8630 modified with vanadium is also used for clad and overlaid components, and post-weld heat treatment must then be carefully controlled to avoid embrittlement at the fusion line.
Testing typically includes chemical analysis to ASTM E415, tensile testing to ASTM A370 and E8 / E8M, Charpy V-notch impact testing to ASTM E23, hardness to ASTM E10, and ultrasonic examination to ASTM A388 for heavy forged sections.
Chemical Composition for Alloy Steel 8630 Round Bar
Element
Symbol
Min
Max
Unit
Carbon
C
0.28
0.33
%
Manganese
Mn
0.70
0.90
%
Silicon
Si
0.15
0.35
%
Phosphorus
P
-
0.035
%
Sulfur
S
-
0.040
%
Nickel
Ni
0.40
0.70
%
Chromium
Cr
0.40
0.60
%
Molybdenum
Mo
0.15
0.25
%
Iron
Fe
Balance
Balance
%
Chemical Composition
View the chemical composition and applicable material limits for AS 8630 Round Bar
Carbon at 0.28-0.33% sets the maximum attainable hardness after quenching. It is deliberately kept in the lower medium range so that the steel retains good toughness and remains weldable with normal precautions, while still hardening enough to reach tensile strengths approaching 1000 MPa after tempering.
Nickel at 0.40-0.70% is the toughening element. It lowers the ductile-to-brittle transition temperature and raises impact energy. That is what lets 8630 pass the low-temperature Charpy requirements used for subsea and cold-climate service. Nickel also contributes to hardenability.
The chromium, at 0.40-0.60%, does most of the work on hardenability and improves tempering resistance, so the steel retains strength at higher tempering temperatures. It also forms carbides that contribute to wear resistance.
Molybdenum at 0.15-0.25% is the most effective of the three additions per unit weight for hardenability, and it plays a second essential role in suppressing temper embrittlement. Without molybdenum, slow cooling through the 375-575 deg C range after tempering would allow phosphorus to segregate to prior austenite grain boundaries and sharply reduce toughness.
Manganese at 0.70-0.90% adds a little more hardenability and ties up sulphur, and silicon at 0.15-0.35% is there as the deoxidiser. Phosphorus and sulphur are held to 0.035% and 0.040% respectively, and are often restricted further by purchaser supplementary requirements for critical service. The resulting carbon equivalent of about 0.65 governs welding procedure.
Mechanical Properties for Alloy Steel 8630 Round Bar
Mechanical Property
Value
Unit
Tensile Strength (annealed)
565 (typical)
MPa
Yield Strength (annealed)
370 (typical)
MPa
Hardness (annealed)
156 - 197 (typical)
HBW
Tensile Strength (normalised)
650 (typical)
MPa
Yield Strength (normalised)
430 (typical)
MPa
Tensile Strength (quenched and tempered)
850 - 1000 (typical)
MPa
Yield Strength 0.2% Proof (quenched and tempered)
690 - 860 (typical)
MPa
Elongation in 50 mm (quenched and tempered)
18 (typical minimum)
%
Reduction of Area (quenched and tempered)
50 (typical minimum)
%
Hardness (quenched and tempered)
255 - 311 (typical)
HBW
Impact / Charpy V-Notch
42 at -46 deg C (typical, quenched and tempered, when specified)
J
Modulus of Elasticity
205 (typical)
GPa
Mechanical Properties
Check the key mechanical properties and performance requirements of AS 8630 Round Bar
ASTM A29 / A29M and ASTM A322 govern composition and quality for Alloy Steel 8630 Round Bar but do not set mandatory mechanical minima, so the values listed are typical for the stated heat-treated condition. Purchasers requiring guaranteed properties specify a quench and temper condition together with a tensile range, minimum yield strength and, for low-temperature or sour service, a Charpy V-notch requirement at a stated test temperature.
Properties are governed by the tempering temperature and by section size. After an oil quench from 845-870 deg C, tempering near 540 deg C gives the upper end of the strength range with reduced ductility, while tempering near 660 deg C gives lower strength with higher elongation, reduction of area and impact energy. Because hardenability is good, the property gradient from surface to centre is far smaller than in plain carbon grades of similar carbon content, and consistent properties can be achieved to roughly 100 mm diameter.
Impact toughness is the principal reason this grade is chosen over 4130 or 4140 in many oilfield applications. The nickel addition sustains useful Charpy energy well below zero, and values around 42 J at -46 deg C are routinely achieved in properly heat-treated material.
Testing is performed to ASTM A370, ASTM E8 / E8M and ASTM E23, with hardness to ASTM E10.
Dimension / Sizes for Alloy Steel 8630 Round Bar
Dimension / Size
Value
Unit
Diameter (available range)
15 - 500
mm
Standard Length
3 - 6
m
Custom Length
Cut to length on request
-
Diameter Tolerance (hot-rolled)
Per ASTM A29 / A29M
-
Diameter Tolerance (cold-finished)
Per ASTM A108 or as agreed
-
Length Tolerance
Per ASTM A29 / A29M or as agreed
-
Straightness Tolerance
Per ASTM A29 / A29M or as agreed
-
End Condition
Square cut, saw cut, chamfered or as ordered
-
Surface Finish
Hot-rolled black, peeled, rough turned, cold-drawn bright, turned ground and polished
-
Cut-to-Length Availability
Available
-
Dimensional Standard
ASTM A29 / A29M and ASTM A108
-
Dimensions & Sizes
Explore available diameters, lengths, and dimensional requirements for AS 8630 Round Bar
Pricing for Alloy Steel 8630 Round Bar
Round Bar Prices are generally quoted per kilograms or meters tonnes and can fluctuate with the global raw material and market prices. The final price will depend on a variety of factors, including the grade size, diameter, length, surface finish, the quantity and whether the bars are cut to length or in standard lengths.
For smaller quantities, we can also quote per metre or per piece basis once the required dimensions have been confirmed. Container-loads or orders that are larger in size are typically priced per tonne, based upon the specifications required and the supply conditions.
Please provide your desired dimensions, grades, length number, and end for a current quote including the lead time applicable and details for certification.
Pricing
Get current Alloy Steel 8630 Round Bar pricing based on size, quantity, grade, finish, and delivery requirements.
Why Choose Us
Euro Steel Bars is an international distributor, stockist and exporter of stainless round steel bars that cover carbon, stainless alloy, special grades. We stock a variety of sizes and grades. We guarantee every order with mill test certificates as well as full quality-assurance documentation. Our name speaks to our roots: European-sourced materials that is backed by the certificates and rigor that buyers from Asia as well as the Gulf and Africa are looking for.
Each bar we deliver is accompanied by EN 10204 3.1 mill test certificates as well as complete documentation of quality, so what you receive corresponds to what’s written in the documents. We carry a selection of sizes and grades ready for transport, and cut length upon the request of customers, which results in quicker lead times, whether you’re ordering just a one-off spec or a complete project tonnage.
We operate an actual wholesale business that is that is supported with an internationally-operated supply chain therefore we are able to serve fabricators sourcing one grade the same way in the same way as an EPC contractor who is placing a large order. Our clients include manufacturers, fabricators EPC construction companies, engineers oil and gas projects as well as construction companies. we design our inventory as well as documentation to show what buyers need to bring projects forward.
Our customers trust us across Qatar, Oman, Bahrain, Kuwait, Jordan, Malaysia, Singapore, Thailand, Taiwan, Turkey, Italy and South Africa. If you’re looking to source an Gulf energy project, or a construction project within Southeast Asia, you get the same quality of certified material, the exact documentation, and the exact delivery procedure.
Frequently Asked Questions
What is Alloy Steel 8630 Round Bar?
What standard does Alloy Steel 8630 Round Bar comply with?
What are the equivalent grades of Alloy Steel 8630?
Why is 8630 preferred over 4130 or 4140 for subsea components?
What heat treatment is applied to 8630?
What are the key mechanical properties of 8630?
Can Alloy Steel 8630 be welded?
What sizes and finishes are available?
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