431 Stainless Precision Ground Rod

Martensitic Stainless Steel Hardened Shafts

431 Stainless Steel Rod AISI 431 | UNS S43100

Strong corrosion resistance is not always easy to achieve in martensitic stainless steel, especially when the application also requires high mechanical strength. 431 stainless steel provides a stronger balance of corrosion resistance, toughness, and strength than many standard martensitic grades.

With its high chromium content and nickel addition, 431 stainless steel is suitable for precision shafts and mechanical components used in demanding environments where load-bearing performance and corrosion resistance must work together. After heat treatment, the material can achieve high strength and hardness while maintaining good resistance to wear and general corrosion.

Compass Power Tech manufactures 431 stainless steel precision ground rods for customers producing shafts, valve parts, pump components, fasteners, mechanical parts, and other precision components that require reliable strength, accurate dimensions, and improved corrosion resistance.

Mechanical Properties

Yield Strength (Rp0.2)	Tensile Strength (Rm)	Elongation (A)	Impact Energy (KV)	Hardness
≥ 690 MPa	≥ 850 MPa	≥ 12%	≥ 24 J	50–60 HRC

QT800 Heat Treatment		QT 900 Heat Treatment
Tensile Strength (Rm)	800–950 MPa	Tensile Strength (Rm)	900–1050 MPa
Yield Point (Re)	> 600 MPa	Yield Point (Re)	> 700 MPa

Chemical Composition (%)

Grade	C	Si	Mn	P	S	Ni	Cr
431 (S43100)	0.95–1.2	≤ 1.00	≤ 1.00	≤ 0.035	≤ 0.030	1.25–2.50	15.0–17.0

Specifications

Diameter	Tolerance	Roundness	Straightness	Standard Length	Surface Roughness
Φ3-Φ25	0.1mm/m	g6, h6, f7	≤1/2	2m 3m	Ra≤0.4
Φ25-Φ40	0.1mm/m ≤	g6, h6, f7	≤1/2	3m, 6m	Ra≤0.4
Φ40-Φ80	0.1mm/m ≤	g6, h6, f7	≤1/2	3m, 6m	Ra≤0.4
Φ80-Φ150	≤0.05mm/m	g6, h6, f7	≤1/2	3m, 6m	Ra≤0.4
Φ150-Φ180	≤0.05mm/m	g6, h6, f7	≤1/2	3m, 6m	Ra≤0.4

Additional Custom Services

Cut-to-length service: Shaft length can be customized according to customer assembly requirements.
End chamfering: Both ends of the shaft can be chamfered to simplify downstream machining and installation.
Drawing-based machining: Shafts can be machined according to customer drawings and supplied as ready-to-assemble components.
Surface rolling treatment: Surface rolling can be applied to improve surface hardness when higher wear resistance is required.

Packaging and Storage

To protect stainless steel precision ground shafting during sea freight and storage, Compass Power Tech uses anti-rust paper tube packaging. Before wrapping, anti-rust oil is applied evenly to the shaft surface, and anti-rust wax is applied inside the paper tube. This protection process helps reduce corrosion risk during transportation and ensures customers receive shafts in stable, ready-to-use condition.

Looking for Custom Metal Components for Your Application?

We manufacture precision ground shafts, stainless steel tubing, piston rods and aluminum alloy cylinder tubes for hydraulic, pneumatic, machinery, energy and transportation applications. Contact us for material selection, specifications and customization support.