1.4057 QT800 Stainless Steel Round Bar

If you are sourcing stainless steel round bars for applications such as pump shafts, valve components, spindles, piston rods, or other mechanical parts, 1.4057 QT800 is an ideal choice. It offers a combination of high strength and heat-treatability, while providing good corrosion resistance in appropriate industrial environments.

 

What is 1.4057 QT800 stainless steel round bar?

EN 1.4057 (grade X17CrNi16-2) is a martensitic chromium-nickel stainless steel, equivalent to AISI 431 or UNS S43100. Unlike common austenitic stainless steels such as grade 304, 1.4057 can achieve higher mechanical strength through quenching and tempering, making it well-suited for components subject to mechanical loads and rotational forces.
The designation "QT800" refers to a "quenched and tempered" delivery condition. According to the EN 10088-3 standard, for round bars within specific size ranges, the tensile strength in the QT800 condition is typically required to be between 800 and 950 MPa.

 

 

1.4507 Steel equivalent

Country	Japan	Germany	USA	China
Standard	JIS	DIN	ASTM	GB/T
Grade	SUS431	X17CrNi16-2/1.4057	431	17Cr16Ni2

 

Chemical Composition of 1.4057 Stainless Steel

Chemical Element	EN 1.4057 Composition (wt.%)
Carbon (C)	0.12–0.22%
Chromium (Cr)	15.0–17.0%
Nickel (Ni)	1.50–2.50%
Silicon (Si)	≤ 1.00%
Manganese (Mn)	≤ 1.50%
Phosphorus (P)	≤ 0.040%
Sulfur (S)	≤ 0.030%

 

Mechanical Properties of 1.4057 QT800 Round Bar

Mechanical Property	Diameter ≤ 60 mm	Diameter > 60–160 mm
0.2% proof strength, Rp0.2	≥ 600 MPa	≥ 600 MPa
Tensile strength, Rm	800–950 MPa	800–950 MPa
Elongation, A5, longitudinal	≥ 14%	≥ 12%
Charpy impact energy, longitudinal	≥ 25 J	≥ 20 J
Delivery condition	QT800	QT800

 

What is the tensile strength of 1.4057 QT800 round bar?

The referenced EN 10088-3 data gives a tensile strength range of 800–950 MPa, with a minimum 0.2% proof strength of 600 MPa. The applicable product dimensions, test direction and purchase specification determine the final acceptance requirements.

 

What is the difference between 1.4057 QT800 and QT900?

QT900 generally offers a higher tensile strength range of 900–1,050 MPa and a minimum proof strength of 700 MPa under the referenced EN data. QT800 has a lower specified strength range. Elongation and impact requirements also differ, so the appropriate condition depends on the design's combined strength and toughness requirements.

Property	QT800	QT900
Tensile strength, Rm	800–950 MPa	900–1,050 MPa
Minimum 0.2% proof strength, Rp0.2	600 MPa	700 MPa
Typical material application	High-strength mechanical components requiring the QT800 condition	Components requiring a higher specified strength condition
Purchasing priority	Balance specified strength with ductility and toughness	Confirm the higher strength requirement and acceptable toughness

 

Heat Treatment of 1.4057 QT800 Stainless Steel Round Bars

For 1.4057 QT800 (X17CrNi16-2) stainless steel, the quenching and tempering (QT) process-in accordance with EN 10088-3-consists of austenitizing at 950–1050°C, with a holding time of 30 minutes per 25 mm of wall thickness, followed by quenching in oil or air. The standard QT800 specification requires a double-tempering treatment: first at 750–800°C, followed by a second tempering at 650–700°C, with air cooling after each stage. It is essential to avoid the 420–520°C temperature range to prevent "475°C embrittlement." This process ensures consistent mechanical properties, achieving a tensile strength of 800–950 MPa and a yield strength of ≥600 MPa.

 

1.4057 stainless steel corrosion resistant?

1.4057 (X17CrNi16-2 / AISI 431) is a martensitic stainless steel with 15.0–17.0% Cr and 1.5–2.5% Ni. It delivers better corrosion resistance than 410 and 420 grades, suitable for fresh water, mild atmospheric and weak organic acid environments. It is not recommended for chloride-rich or strong acid service, where pitting corrosion will easily occur. 

 

Can 1.4057 QT800 round bar be machined?

1.4057 QT800 round bar has good machinability in quenched and tempered condition. Its hardness typically sits at 240–300 HB. Stable strength and uniform microstructure support turning, milling and grinding. Cutting parameters need adjustment compared with annealed stock. Tool wear is higher than austenitic stainless steel such as 304, and sufficient coolant is required.

 

Can 1.4057 QT800 round bar be welded?

1.4057 QT800 can be welded but with strict limits. Its martensitic structure is prone to hardening and cracking in the heat-affected zone. Preheat to 200–300°C and post-weld tempering at 600–680°C are mandatory. Matching martensitic filler metal is required. It is not preferred for heavy welded structures, and welded joints lose QT800 strength.

 

Is 1.4057 suitable for pump shafts and valve components?

Yes, 1.4057 QT800 is widely selected for pump shafts and valve parts. Its quenched and tempered condition provides tensile strength 800–950 MPa, good toughness and moderate corrosion resistance. It resists wear and galling under dynamic load. It is ideal for fresh water and light chemical media, but not a candidate for harsh chloride or highly corrosive process fluids.

 

Supplier of 1.4057 QT800 Stainless Steel Round Bars

GNEE is a reliable supplier of stainless steel round bars, including grade 1.4057. These bars are typically available in diameters ranging from Ø6 mm to Ø450 mm and can be supplied in either a solution-annealed or solution-annealed and age-hardened condition.

Production Method	Diameter Range (mm)	Standard Length (m)	Dimensional Tolerance	Surface Finish
Hot-Rolled Round Bar	Ø 12–120 mm	3.0–6.0 m (or SRL/DRL)	ISO h11 / EN 10060	Black / Peeled
Forged Round Bar	Ø 120–500 mm	2.0–6.0 m	DIN 7527 / Custom	Black / Rough-Turned
Bright / Peeled Round Bar	Ø 15–300 mm	3.0–6.0 m	ISO h9 / h10 / h11	Turned / Polished
Centerless-Ground Round Bar	Ø 6–80 mm	3.0–6.0 m	ISO h7 / h8	Ground / Bright

Note: Actual size ranges, lengths, tolerances, and surface finishes depend on the material condition, production method, and supplier confirmation.

Contact now

All stainless steel round bars are manufactured in accordance with ASTM A276 and ASTM A479 standards, and an EN 10204 3.1 quality certificate can be provided with the shipment.

GNEE offers a variety of product forms-such as hot-rolled, forged, peeled, polished, and cut-to-length round bars-to meet diverse processing and performance requirements.
For packaging and transport, the round bars are treated with anti-rust oil, wrapped in plastic film, and then either packed in seaworthy wooden crates or bundled and secured with steel straps.