Stainless Steel 440C Round Bar
➡️ SS 440C | UNS S44004 | EN 1.4125
➡️ ASTM, EN, JIS & International Standards
➡️ Supply Conditions
➡️ Multiple Diameters & Supply Lengths
➡️ Global Export & International Delivery
Country of Origin:
Europe, Japan, USA
Material Type:
Stainless Steel
UNS Number:
S44004
Wr. No.:
1.4125
MTC Available:
EN 10204 3.1
Product Description for Stainless Steel 440C Round Bar
Type 440C (UNS S44004) is a high-carbon martensitic stainless steel, and bar is supplied to ASTM A276 / A276M with dimensions to ASTM A484 / A484M. European practice specifies it as grade 1.4125 to EN 10088-3.
Carbon runs 0.95-1.20%, far higher than any other common stainless grade, with 16-18% chromium and up to 0.75% molybdenum. That carbon level is the point: after hardening it produces a martensitic matrix loaded with hard chromium carbides, and the result is the highest hardness and wear resistance available from a stainless steel, typically 58-60 HRC.
Corrosion resistance is moderate and only reaches its best in the hardened and tempered condition, where chromium is properly distributed. It is adequate for fresh water, mild atmospheric exposure, food contact and many petroleum applications, but well short of an austenitic grade in chlorides.
Bar is supplied annealed for machining, then hardened by the customer at roughly 1010-1065 C, quenched, and tempered low at 150-370 C. Machining is done annealed, since hardened 440C is essentially a grinding-only material.
A sub-zero treatment between quenching and tempering is normal practice for precision parts, since it converts retained austenite and gives dimensional stability.
Available from 6 mm to 250 mm, hot-finished or cold-finished. The structure is martensitic, so the bar is magnetic in every condition, and for bearing work VAR or ESR remelted material is usually specified because inclusions govern rolling contact fatigue life.
Typical work is bearing races and balls, valve seats and trim, pump wear parts, cutlery and surgical blades, knife stock, moulds, gauges and wear plates.
Common Applications of Stainless Steel 440C 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 SS 440C Round Bar
Standard
Country / Region
Grade
ASTM A276 / A276M
USA
Type 440C (UNS S44004)
ASTM A484 / A484M
USA
UNS S44004 (dimensional requirements)
EN 10088-3
Europe / EU
1.4125 (X105CrMo17)
BS EN 10088-3
United Kingdom
1.4125
JIS G4303
Japan
SUS 440C
GB/T 1220
China
102Cr17Mo
KS D 3706
South Korea
STS 440C
ISO 15510
International
X105CrMo17
Technical Specification for Stainless Steel 440C Round Bar
Specification
Value
Unit
Material
Stainless steel
-
Grade
440C / UNS S44004 / 1.4125
-
Product Form
Round bar / rod
-
Standard
ASTM A276 / A276M
-
Diameter
6 - 250 (typical supply range)
mm
Length
3 - 6 (random), or cut to length
m
Manufacturing Process
Hot rolled or forged, annealed for machining
-
Production Route
EAF + AOD refining, with VAR or ESR remelt for bearing quality
-
Surface Finish
Hot-rolled and annealed, cold-drawn, peeled, turned, centreless ground
-
Heat Treatment / Delivery Condition
Supplied annealed 840-870 C slow cooled, hardened by user
-
Hardening Treatment
Austenitise 1010-1065 C, oil or air quench, temper 150-370 C
-
Tolerance Standard
ASTM A484 / A484M
-
Density
7.68 (typical)
g/cm3
Melting Range
1370 - 1480 (typical)
C
Thermal Conductivity at 100 C
24.2 (typical)
W/m.K
Coefficient of Thermal Expansion (20-100 C)
10.1 (typical)
um/m.C
Specific Heat (0-100 C)
460 (typical)
J/kg.K
Electrical Resistivity at 20 C
0.60 (typical)
uOhm.m
Modulus of Elasticity at 20 C
200 (typical)
GPa
Magnetic Properties
Ferromagnetic in all conditions
-
Maximum Service Temperature
425 (typical, above which tempering softens the material)
C
Testing / Inspection Standard
ASTM A370 for mechanical testing and hardness
-
Certification / Inspection Documents
EN 10204 3.1 or 3.2 mill test certificate
-
Technical Specifications
Get the key technical specifications for Stainless Steel 440C Round Bar
Buy to ASTM A276 / A276M under UNS S44004, with dimensional tolerance, straightness and surface condition to ASTM A484 / A484M. European supply is to EN 10088-3 as 1.4125 (X105CrMo17).
The normal delivery condition is annealed, roughly 840-870 C followed by slow cooling, which brings hardness down to around 269 HB maximum so the material can be machined. Hardening is then carried out by the customer after machining: austenitise at 1010-1065 C, oil or air quench depending on section, and temper at 150-370 C. A sub-zero treatment is often added between quenching and tempering to convert retained austenite, which matters for dimensional stability in bearings and gauges.
Tempering choice needs care. Tempering between roughly 425 C and 565 C should be avoided, because it reduces both toughness and corrosion resistance. Above about 425 C in service, the material simply tempers further and softens, so that is the practical service ceiling.
Corrosion resistance is best in the hardened and tempered condition and is noticeably worse annealed, since chromium is tied up in coarse carbides rather than distributed.
For bearing and precision applications, VAR or ESR remelted material is frequently specified along with cleanliness rating and ultrasonic examination, because inclusions govern rolling contact fatigue life.
Chemical Composition for Stainless Steel 440C Round Bar
Element
Symbol
Min
Max
Unit
Carbon
C
0.95
1.20
%
Manganese
Mn
-
1.00
%
Silicon
Si
-
1.00
%
Phosphorus
P
-
0.040
%
Sulfur
S
-
0.030
%
Chromium
Cr
16.00
18.00
%
Molybdenum
Mo
-
0.75
%
Iron
Fe
Balance
-
%
Chemical Composition
View the chemical composition and applicable material limits for SS 440C Round Bar
Carbon at 0.95-1.20% is what makes this grade what it is, and the level is extraordinary for a stainless steel. Part of it dissolves into the austenite before quenching and produces a very hard martensite. The rest stays as primary chromium carbides distributed through the matrix, and those carbides are what deliver the abrasion and wear resistance the grade is bought for. Carbon this high also explains why 440C is difficult to machine hardened, effectively unweldable, and low in toughness.
Chromium at 16.00-18.00% has to be high for two reasons at once. It lays down the passive film that makes the steel stainless, and it also combines with carbon to form the chromium carbides. Because a significant share of the chromium ends up locked in carbides rather than dissolved in the matrix, the effective chromium available for corrosion protection is well below the nominal figure, which is why 440C is only moderately corrosion resistant despite carrying as much chromium as Type 430.
Molybdenum up to 0.75% is permitted rather than required, and where present it improves hardenability and pitting resistance slightly.
Manganese and silicon deoxidise and assist hardenability. Phosphorus and sulphur are residuals held low to protect what toughness the grade has, and premium bearing-quality material runs them well below the maxima.
Mechanical Properties for Stainless Steel 440C Round Bar
Mechanical Property
Value
Unit
Hardness, annealed condition
269
HBW (maximum, ASTM A276)
Hardness, annealed and cold drawn
285
HBW (maximum, ASTM A276)
Tensile Strength, hardened and tempered at 204 C
2030
MPa (typical)
Yield Strength 0.2% Proof, hardened and tempered at 204 C
1900
MPa (typical)
Elongation in 50 mm, hardened and tempered at 204 C
4
% (typical)
Hardness, hardened and tempered at 204 C
59
HRC (typical)
Modulus of Elasticity
200
GPa (typical)
Mechanical Properties
Check the key mechanical properties and performance requirements of SS 440C Round Bar
Two very different sets of properties apply to this grade, so the condition must always be stated alongside any figure. ASTM A276 / A276M controls the annealed condition through a hardness ceiling of 269 HBW, rising to 285 HBW for annealed and cold-drawn bar. Those ceilings are what keep the bar machinable. The hardened and tempered values shown are typical of material austenitised at 1010-1065 C, quenched and tempered near 204 C, and they are indicative rather than mandatory acceptance limits, since hardening is normally carried out by the customer after machining.
Hardened 440C reaches roughly 58-60 HRC, the highest of any stainless steel, with tensile strength around 2030 MPa. Ductility is almost nil at about 4% elongation, and impact toughness is low. This is a wear-resistant material, not a structural one, and it should not be used where shock loading or bending is expected.
Tempering temperature sets the balance. Low tempering at 150-260 C keeps maximum hardness. Higher tempering trades hardness for a little toughness, but tempering between roughly 425 C and 565 C must be avoided, because it costs both toughness and corrosion resistance at once.
Retained austenite after quenching is a real concern in precision parts, and a sub-zero treatment before tempering is normal practice where dimensional stability matters.
Dimension / Sizes for Stainless Steel 440C Round Bar
Dimension / Size
Value
Unit
Diameter
6 - 250
mm
Standard Length
3 - 6 (random / mill lengths)
m
Custom Length
Cut to length available on request
-
Diameter Tolerance
Per ASTM A484 / A484M, varies with size and finish class
-
Length Tolerance
Per ASTM A484 / A484M or as agreed at order
-
Straightness Tolerance
Per ASTM A484 / A484M or as agreed at order
-
End Condition
Square cut, chamfered, or as ordered
-
Surface Finish
Hot-rolled and annealed, cold-drawn, peeled, turned, centreless ground
-
Available Size Range
6 - 250, larger diameters by forging on enquiry
mm
Cut-to-Length Availability
Available
-
Dimensional Standard
ASTM A484 / A484M
-
Dimensions & Sizes
Explore available diameters, lengths, and dimensional requirements for SS 440C Round Bar
Pricing for Stainless Steel 440C 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 Stainless Steel 440C 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 Stainless Steel 440C Round Bar?
What hardness can 440C reach?
What standard does Stainless Steel 440C Round Bar comply with?
What are the equivalent grades of Stainless Steel 440C Round Bar?
How corrosion resistant is 440C?
Can 440C Round Bar be welded?
Why is a sub-zero treatment used with 440C?
What sizes and lengths are available?
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