Nauticalloy 4307 304L | 1.4307

Nauticalloy 4307 is an economical alternative solution for marine applications where moderate strength and corrosion resistance characteristics are adequate for the operational requirements.

This versatile low-carbon austenitic stainless steel provides reliable performance and excellent fabrication characteristics whilst offering significant cost advantages compared to higher-alloy marine grades.

The optimised austenitic composition delivers dependable performance in controlled marine environments, making it the preferred choice for applications where premium corrosion resistance is not essential whilst maintaining the excellent formability and weldability inherent to austenitic stainless steels.

1.4307

Material equivalents

Nauticalloy 4307 is known also under different designations and matches marine shafts in 1.4307, AISI 304L, UNS S30403, 304S11. All are internationally recognised under various systems, ensuring global specification compatibility and supply chain reliability across the various marine markets.

View Nauticalloy 4307 data sheet

Chemical Composition

Element	C	Si	Mn	P	S	Cr	Ni	Mo	N
% min	-	-	-	-	-	17.50	8.00	-	-
% max	0.03	1.00	2.00	0.045	0.03	19.50	10.50	-	0.11

Chemical composition (% by weight)

Mechanical properties

Property	Rp0.2 (Proof Strength)	UTS (Tensile Strength)	Elongation A4 %	Reduction of Area %	Hardness BHN (max)
Metric (MPa / N/mm²)	>205 MPa	515 - 680 MPa	45	25	<170
Imperial (ksi)	>30 ksi	75 - 100 ksi	45	25	<170

Characteristics

Low-carbon austenitic structure

Nauticalloy 4307 features a low-carbon austenitic microstructure with maximum carbon content of 0.03%, providing excellent resistance to carbide precipitation during welding and thermal processing. This composition significantly improves intergranular corrosion resistance compared to standard 304-1.4301 grade.

General purpose corrosion resistance

The chromium-nickel austenitic composition provides good resistance to atmospheric corrosion, organic and inorganic chemicals, oxidising acids including nitric acid, and caustic solutions at moderate temperatures. The material demonstrates reliable performance in controlled marine atmospheric conditions.

Excellent formability

The austenitic structure enables severe deep drawing capabilities, making this grade suitable for complex marine component geometries requiring extensive forming operations whilst maintaining structural integrity and surface quality.

Superior welding properties

The low-carbon composition ensures exceptional weldability without post-weld heat treatment requirements, maintaining corrosion resistance properties in heat-affected zones and providing cost-effective fabrication for a wide range of applications.

Marine applications and benefits

SuperYacht 107m Nauticalloy 4307 finds application in marine components where moderate corrosion resistance and good fabrication characteristics are adequate, including non-critical marine hardware, internal marine structural elements and marine equipment operating in controlled atmospheric conditions.

Cleanability, good corrosion resistance to food products and approved food-contact surface characteristics make this grade suitable for galley equipment and food preparation surfaces.

Applications extend to architectural elements, decorative fittings and components where aesthetic appearance, formability and cost-effectiveness are primary considerations rather than extreme corrosion resistance.

The material provides adequate performance for marine fasteners, brackets and general hardware applications in above-waterline marine environments where direct seawater contact is limited.

Processing Quality Assurance Nauticalloy 4462 Nauticalloy 4542 Nauticalloy 4404 Nauticalloy 4501

For Nauticalloy 4307 technical consultation, contact our specialist technical sales team at +44 (0)1902 409409 or email sales@millstockstainless.com

Nauticalloy 4307