ASTM A693 Type 630 Stainless Steel Plate

As a stainless steel supplier and China mill-direct exporter, SHH STEEL supplies ASTM A693 Type 630 (UNS S17400) Stainless Steel Plate. Type 630 (UNS S17400) is a martensitic precipitation-hardening stainless steel with 15.00 – 17.50 % chromium, 3.00 – 5.00 % nickel, 3.00 – 5.00 % copper and 0.15 – 0.45 % niobium plus tantalum. It is supplied solution treated and hardened by a single ageing treatment.

Type 630 is the martensitic precipitation-hardening grade of ASTM A693, and SHH STEEL supplies the standard grade. Its European counterpart is EN 10088-2 1.4542 plate, and its Japanese counterpart is JIS G4305 SUS630 steel plate.

This page summarises the requirements for ASTM A693 Type 630 plate and sheet: chemical composition, mechanical properties, heat treatment and the general delivery requirements of ASTM A480/A480M. Values are taken from ASME SA-693 (2023 BPVC Section II-A), which is identical with ASTM A693-02ε1 except for changes to the XM-16 elongation, the maximum hardness of XM-12 and 630 in Table 5 and Note B of Table 1; check the ASTM edition named on your order. SHH STEEL confirms the edition named on the drawing before an order is placed.

ASTM A693 requires the heat treatment to be stated on the purchase order (clause 3.1.3.1). Material is furnished solution treated and must be capable of developing the Table 5 properties after precipitation hardening; no bend test is required for Type 630 (Table 6).

Copper provides the precipitation hardening, and niobium ties up carbon.

Elongation in Table 5 rises with thickness, for example 5 %, 8 % and 10 % in H900 for under 4.76 mm, 4.76 – 15.88 mm and over 15.88 mm. Charpy V values are given for H1025 and softer conditions over 4.76 mm.

The customer usually machines the solution-treated plate and then ages it; the lower the ageing temperature, the higher the strength and the lower the toughness.

Lead time from the mill is normally 30 – 40 days after order confirmation, depending on size, finish and rolling schedule. Dimensional tolerances follow ASTM A480/A480M unless the order states otherwise.

• Martensitic precipitation-hardening grade hardened by copper.
• H900: ≥ 1 310 MPa tensile, ≥ 1 170 MPa yield.
• Single-step ageing between 482 and 621 °C.
• No bend test required (A693 Table 6).
• Ordered by standard and UNS number: ASTM A693 Type 630, UNS S17400.

Because EN, JIS and ASTM name and test the hardened conditions differently, a substitution must be checked condition by condition. For the semi-austenitic Type 631 (UNS S17700), see EN 10088-2 1.4568 plate and GB/T 4237 07Cr17Ni7Al S51770 plate.

Euro Inox lists bolts and spindles in fittings and compressor parts for the EN equivalent 1.4542, and JSSA lists high-strength bolts, valves, aircraft parts and shafts for SUS630. Typical plate applications include:

• High-strength bolts and spindles machined from plate
• Valve parts
• Compressor parts
• Aircraft parts
• Shafts

A693 notes that these steels are used for parts needing corrosion resistance and high strength at room temperature or up to 315 °C. SHH STEEL supplies 630 stainless steel plate for these uses as full plates or cut-to-size blanks.

ASTM A693 covers several precipitation-hardening grades. The table compares Type 630 with the grades most often considered alongside it, using Tables 1, 3 and 6 of SA-693 (identical with A693-02ε1 apart from the listed changes).

Type 630 and XM-12 are martensitic grades hardened by copper; 631 and 632 are semi-austenitic grades hardened by aluminium; XM-13 is a martensitic aluminium-hardened grade. The EN counterpart of 630 is EN 10088-2 1.4542 and the Japanese counterpart is JIS G4305 SUS630; for the semi-austenitic 631 type see EN 10088-2 1.4568 and GB/T 4237 S51770. SHH STEEL can quote these grades side by side.

Thicker plate has higher elongation and reduction-of-area minimums, and the softer conditions add Charpy V requirements over 4.76 mm. Where toughness matters, designers often choose H1025 or higher ageing temperatures rather than H900. SHH STEEL confirms that the certificate reports the tests for the thickness band ordered.

JSSA gives SUS630, the JIS counterpart, a pitting index (Cr + 3.3 Mo) of about 16.0, the level of a 16 % chromium steel without molybdenum. Euro Inox describes the EN equivalent 1.4542 as resistant to water and dilute acids. Type 630 is therefore chosen for strength with moderate corrosion resistance, not for aggressive chloride service.

A693 states that these steels are used for parts requiring corrosion resistance and high strength at room temperature or at temperatures up to 315 °C. The ageing temperature also affects behaviour in service: higher ageing temperatures (H1025 to H1150) give lower strength but better toughness, which is often preferred where stress corrosion cracking or hydrogen embrittlement is a concern. SHH STEEL can help the buyer choose the condition with the designer.

These are typical values published for the EN equivalent and are not requirements of ASTM A693. Type 630 is magnetic in the solution-treated and hardened conditions. On request, SHH STEEL can pass on the producing mill’s data sheet.

A693 notes that these steels are suitable for machining in the solution-annealed condition, after which they may be hardened to the Table 5 properties without danger of cracking or distortion. Type 630 is capable of mild forming only, so forming should be limited and done before hardening. Machining allowances should consider the small dimensional change on ageing.

For the EN equivalent 1.4542, Euro Inox lists matching 1.4542 filler material. Welding is normally done in the solution-treated condition, and the welded part is then aged so that weld and base metal respond together. SHH STEEL can supply Type 630 plate cut to size for machining.

ASTM A693 clause 4 allows the steel to be melted in an electric furnace (with optional separate degassing and refining) or a vacuum furnace, optionally followed by consumable remelting in vacuum, inert gas or electroslag, or by electron beam refining; other commercial methods may be agreed. General requirements for sampling, testing, retests and certification follow ASTM A480/A480M.

• Clause 6: material is furnished solution annealed unless the purchase order specifies another condition.
• Clause 7: test specimens must meet Table 4 in the delivered condition and be capable of meeting Table 5 after hardening.
• Clause 8: solution-annealed samples must pass the cold bend of Table 6 without cracking on the outside of the bend.
• Clause 9: samples are hardened as specified in Tables 2 and 3 to verify the Table 5 properties.

SHH STEEL checks that the certificate reports both the delivered-condition results and the results on hardened samples for the condition ordered, and can arrange third-party witness testing for Type 630.

• Specification: ASTM A693 or ASME SA-693, with edition.
• Grade: Type 630, UNS number.
• Product form and dimensions: plate, sheet or strip; thickness, width, length, quantity.
• Heat treatment: A693 clause 3.1.3.1 requires it to be stated on the purchase order (delivery condition and, where relevant, the hardened condition to be verified).
• Hardened condition to be verified on test samples (for example H1025 or H1150)
• Inspection document (3.1 or 3.2) and any third-party inspection.
• Marking, packing and destination.

SHH STEEL reviews the order against A693 before it is placed and confirms in writing any requirement the mill cannot meet.

The condition names follow the ageing temperature in degrees Fahrenheit, as SA-693 Table 3 shows: H900 is aged at 900 °F (482 °C) for 1 hour, H925, H1025, H1075, H1100 and H1150 at 925 – 1 150 °F (496 – 621 °C) for 4 hours, and H1150M adds a first step at 1 400 °F (760 °C) for 2 hours before ageing at 1 150 °F. The lower the ageing temperature, the higher the strength: tensile strength falls from 1 310 MPa in H900 to 930 MPa in H1150 and 790 MPa in H1150M, while elongation, reduction of area and impact energy rise.

Where a part needs more toughness than strength, designers often choose H1025 or H1150. For weldable martensitic plate with high strength but no ageing step, EN 10088-2 1.4418 is sometimes compared. SHH STEEL can help the buyer match the condition to the drawing.

The strength levels of the two standards are almost identical, but elongation bands differ: JIS uses thickness bands of up to 5.0 mm, 5.0 – 15.0 mm and over 15.0 mm, while A693 uses under 4.76 mm, 4.76 – 15.88 mm and over 15.88 mm, and A693 adds Charpy V values for H1025 and softer conditions over 4.76 mm. A heat for dual certification must meet both. SHH STEEL checks both tables when a drawing names both standards.

Plate weight is calculated from the dimensions and the density. Using 7.8 g/cm³ (Euro Inox, EN 1.4542), one square metre of Type 630 plate 1 mm thick weighs 7.8 kg, so the mass of a plate is density × thickness (mm) × width (m) × length (m).

Actual weight differs from theoretical weight because of thickness tolerance; whether the invoice uses theoretical or actual weight should be agreed at the order. SHH STEEL shows both on the packing list.

As an experienced Type 630 supplier, we find that buyers usually worry less about price than about getting the right material on time. The table below lists the concerns we hear most often and how SHH STEEL deals with each one.

SHH STEEL also offers steel cutting services, bending and forming services, a third-party testing service with partner laboratories, and a worldwide shipping service. See our full range of stainless steel sheets and plates.

ASTM A693 Type 630 (UNS S17400) Stainless Steel Plate is the martensitic precipitation-hardening grade of ASTM A693, supplied solution treated and aged by the user to conditions from H900 to H1150M. SHH STEEL supplies it with full ASTM A693 compliance, 3.1 inspection certificates and optional third-party testing, with a normal lead time of 30 – 40 days. Contact SHH STEEL for availability, sizes and a quotation for your Type 630 requirement.