Stainless Steel 420F Round Bar
➡️ SS 420F | UNS S42020 | EN 1.4029 | X29CrS13 | AISI 420F | ASTM A582
➡️ 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:
S42020
Wr. No.:
1.4029
MTC Available:
EN 10204 3.1
Product Description for Stainless Steel 420F Round Bar
Stainless Steel 420F Round Bar is a free-machining, high-carbon martensitic stainless bar made to UNS S42020. It contains 12–14% chromium, 0.30–0.40% carbon and at least 0.15% sulfur. The sulfur forms manganese sulfide particles that break chips and improve tool life, while the higher carbon allows the bar to reach high hardness after heat treatment.
The grade combines the hardenability of Type 420 with much easier machining. It is widely used where parts must be machined in large numbers and then hardened for wear resistance. Bars are produced to ASTM A582 / A582M and are normally supplied annealed for best machinability.
After hardening and tempering the material gives good hardness and moderate corrosion resistance in mild atmospheres, fresh water, steam, food products and mild chemicals. Corrosion resistance is lower than standard 420 because of the sulfide particles. Best corrosion performance is reached in the hardened condition with a smooth, passivated surface.
420F is strongly magnetic whether annealed or hardened. Welding is not recommended because of the high carbon and sulfur levels.
Common parts include valve trim, pump parts, shafts, gears, bushings, nozzles, cutlery components, surgical and dental instrument parts, and precision parts for automatic lathes. Japan has a matching grade, SUS420F in JIS G4303. The closest European grade is 1.4029 (X29CrS13), which is similar but has lower carbon and is not a direct equivalent. It is a practical grade for wear parts that must be turned in large quantities before hardening. 420F is common in valve trim, pump shafts, gears for food mixers and measuring tools where parts are turned in volume and then hardened. Its sulfur-bearing structure keeps tool wear low, which is a real saving when thousands of small parts are produced from bar stock.
Common Applications of Stainless Steel 420F 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 420F Round Bar
Standard
Country / Region
Grade
UNS
USA
UNS S42020
AISI / ASTM
USA
AISI 420F / ASTM A582 / ASTM A276 / AMS 5620
EN 10088-3
Europe
1.4029 (X33CrS13) / 1.4035 (X46CrS13)
BS 970
United Kingdom
420S37
JIS G4303
Japan
SUS 420F (JIS G4303 / G4309)
GB/T 1220
China
Y3Cr13
KS D 3706
South Korea
STS 420F
AFNOR
France
Z30CF13 / Z20CMF13
Technical Specification for Stainless Steel 420F Round Bar
Specification
Value
Unit
Material
Stainless steel
-
Grade
420F / UNS S42020
-
Standard
ASTM A582 / A582M
-
Product Form
Round bar
-
Diameter (supply range)
3–150
mm
Length (random)
3–6
m
Manufacturing Process
Hot rolled, cold drawn, turned or ground
-
Surface Finish
Hot finished, cold drawn, turned, centreless ground
-
Heat Treatment / Delivery Condition
Annealed (Condition A) or as ordered
-
Tolerance Standard
ASTM A484 / A484M
-
Density
7.7
g/cm³
Melting Range
1450–1510
°C
Thermal Conductivity at 100°C
25
W/m·K
Coefficient of Thermal Expansion 0–100°C
10.3
µm/m·K
Specific Heat at 20°C
460
J/kg·K
Electrical Resistivity at 20°C
0.55
µΩ·m
Modulus of Elasticity at 20°C
200
GPa
Magnetic Properties
Ferromagnetic
-
Testing / Inspection
Chemical analysis, hardness, dimensional and visual check
-
Certification
EN 10204 3.1 mill test certificate
-
Technical Specifications
Get the key technical specifications for Stainless Steel 420F Round Bar
Stainless Steel 420F Round Bar is ordered to ASTM A582 / A582M for free-machining stainless steel bars. General requirements for tolerances, straightness and surface condition come from ASTM A484 / A484M.
Bars are usually supplied annealed, with hardness controlled by the standard. This is the best condition for machining. After machining, parts are hardened by heating to about 980–1040°C, quenching in oil or air and tempering at a temperature that suits the required hardness.
Cold-drawn and centreless ground bars are common for automatic lathe work because they give close diameter tolerances and good straightness. Surface finish and tolerance class should be agreed at order stage.
Density, expansion and conductivity figures for 420F are reference data, not acceptance values. The grade is magnetic. Mill inspection of 420F covers sulfur and carbon content, annealed hardness and bar size. For best corrosion resistance, finished parts should be hardened, cleaned and passivated using a method suited to free-machining stainless steel.
Most 420F bar is supplied annealed for machining, with hardness usually limited to about 262 HB or lower in Condition A. If parts will be hardened in-house, ask for the supplier’s recommended austenitising and tempering temperatures, because hardness response varies slightly between heats. Straightness matters for long shafts, so state the required straightness tolerance on the order.
Chemical Composition for Stainless Steel 420F Round Bar
Element
Symbol
Min
Max
Unit
Carbon
C
0.30
0.40
%
Manganese
Mn
-
1.25
%
Silicon
Si
-
1.00
%
Phosphorus
P
-
0.060
%
Sulfur
S
0.15
-
%
Chromium
Cr
12.0
14.0
%
Nickel
Ni
-
0.50
%
Copper
Cu
-
0.60
%
Chemical Composition
View the chemical composition and applicable material limits for SS 420F Round Bar
The limits shown are for UNS S42020 in ASTM A582. The grade is built on the 13% chromium martensitic base of Type 420, with a higher and tighter carbon range and a sulfur addition for machinability.
Chromium at 12–14% provides the passive film that gives basic corrosion resistance. Carbon at 0.30–0.40% allows the steel to form hard martensite on quenching. This gives the high hardness and wear resistance needed for valve trim, nozzles and instrument parts.
Sulfur at 0.15% minimum combines with manganese to form manganese sulfide particles. These particles break chips, lower cutting forces and extend tool life. The trade-off is lower corrosion resistance, lower transverse ductility and poor weldability compared with non-free-machining 420.
In 420F, silicon and manganese mainly deoxidise the melt, and manganese also forms the sulfides that break chips. Phosphorus is allowed up to 0.060% to help machinability. Nickel and copper are residual elements limited so that they do not affect heat treatment response. The heat analysis on the mill certificate should always be checked against the ASTM A582 limits. Because the carbon range is fairly wide, two heats of 420F can harden to different levels. For tight hardness bands, ask for a heat with carbon near the middle or upper part of the range, and record the heat number on the drawing. For wear parts, higher carbon within the range also helps.
Mechanical Properties for Stainless Steel 420F Round Bar
Mechanical Property
Value
Unit
Hardness (ASTM A582, annealed Condition A)
≤ 262
HB
Tensile Strength (annealed)
655
MPa
Yield Strength 0.2% (annealed)
380
MPa
Elongation (annealed)
22
%
Hardness (hardened and low-temperature tempered)
48–52
HRC
Mechanical Properties
Check the key mechanical properties and performance requirements of SS 420F Round Bar
ASTM A582 uses hardness as the acceptance test for annealed free-machining bars, with a maximum of 262 HB for 420F in Condition A. The tensile, yield and elongation values shown are reference figures for annealed bar and are not mandatory minimums.
The high carbon content gives a strong response to hardening. After quenching and tempering at a low temperature, hardness in the range of about 48–52 HRC is normal. Higher tempering temperatures lower hardness but improve toughness. The final values depend on section size, hardening temperature, quench speed and tempering practice.
Tempering in the range of about 425–565°C is usually avoided because it can reduce impact toughness and corrosion resistance. Because of the sulfide particles, ductility across the bar is lower than in standard 420. Parts that see heavy impact or bending should be reviewed carefully. Buyers should state the required condition and hardness on the order. Hardness in the hardened condition depends on section size and tempering temperature. Thin sections harden fully in air, while thick sections may need oil quenching. Always specify the target hardness range on the drawing rather than only the grade name.
Dimension / Sizes for Stainless Steel 420F Round Bar
Dimension / Size
Value
Unit
Available Diameter Range (supply capability)
3–150
mm
Standard Length (random)
3–6
m
Custom / Cut-to-Length
Available on request
-
Diameter Tolerance
Per ASTM A484 / A484M, cold-finished tolerance class for bright and ground bars
-
Length Tolerance
Per ordered standard or as agreed (commonly +50 / -0 mm for cut lengths)
-
Straightness Tolerance
Per ASTM A484 or as agreed for automatic lathe bars
-
End Condition
Saw cut square, chamfered or as ordered
-
Surface Finish
Hot finished, cold drawn, turned, centreless ground, polished
-
Dimensions & Sizes
Explore available diameters, lengths, and dimensional requirements for SS 420F Round Bar
Pricing for Stainless Steel 420F 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 420F 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
When should I choose 420F instead of standard 420?
What hardness can 420F round bar reach?
Can 420F be polished to a mirror finish?
What is the difference between 420F and 416?
How is 420F heat treated after machining?
What problems can occur when using 420F?
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