Inconel 625 Forged Ring (UNS N06625): Rolled Ring Forging, Sizes and Uses

Quick answer: An Inconel 625 forged ring (UNS N06625) is a seamless annular forging made by ring-rolling a pierced blank — no weld seam, forged grain flow all the way round. The ring in our yard is marked "Ø912/Ø632 ×78", meaning 912 mm outside diameter, 632 mm inside diameter and 78 mm axial height (a 140 mm wall). It pairs 625's corrosion resistance — seawater, acids, sour gas, from cryogenic to ~650 °C — with the soundness of a wrought forging. Specify OD / ID / height, grade N06625, standard (ASTM B564 / ASME SB564), condition and any ultrasonic test.

What a forged ring actually is

A rolled ring forging starts as a pierced disc or upset billet, then is widened and thinned on a ring-rolling mill into a seamless annulus. Because there is no weld and the metal has been worked circumferentially, the grain flow follows the ring — exactly what you want for pressure, rotating and fatigue-loaded parts. For the forged-stock side of this, see our forged round billets guide.

Reading the mark "Ø912/Ø632 ×78"

That notation is the standard way a forge calls out a ring: two diameters and a height, all in millimetres.

Why specify 625 for a ring

If your service is pure high heat rather than corrosion, a 601 ring or billet may be the better call; for load where strength is secondary, see cast vs forged.

Size envelope we roll

The 912 / 632 × 78 ring in the photo sits mid-range — a heavy-wall industrial ring, not a thin-section bearing race.

Standards and grades

• Inconel 625: ASTM B564 / ASME SB564, UNS N06625 (also supplied to NACE MR0175).
• Other ring grades we roll: Inconel 600/601/718, Incoloy 800/825, Hastelloy C-276, Monel 400, duplex and austenitic stainless (304/316/F6NM), and carbon/low-alloy steel.
• Heat-treat condition: annealed (solution-annealed) is standard for 625; age-hardened variants exist for higher strength.

Mechanical properties (625, annealed, ASTM B564)

These are the B564 minimums; typical mill values are at or above them. Confirm on the MTC per our mill-test-certificate guide.

Quality and inspection on a forged ring

• Ultrasonic testing to ASTM A388 / EN 10228-3 across the ring body and faces.
• Dimensional check of OD, ID, height, concentricity and flatness of the faces.
• Chemical analysis and grain-size / macro-etch as agreed.
• Traceability — heat number on the ring and on the cert.

Inconel 625 forged-ring RFQ checklist

1. OD / ID / height (mm) — or give ID and wall if easier.
2. Grade N06625 and standard (B564/SB564), NACE if required.
3. Condition: annealed, or age-hardened for higher strength.
4. Quantity and any machining (facing, drilling, contouring) — or leave as-rolled for your shop.
5. UT and dimensional tolerance (e.g. face flatness, OD/ID bands).
6. Delivery: raw forged ring, or finish-machined to a disc/flange blank.

FAQ

Q: Is a forged ring stronger than a welded ring? A: Yes for the same material — the seamless forged ring has continuous circumferential grain flow and no weld seam, so it resists pressure, fatigue and creep better than a rolled-and-welded ring.

Q: What does "Ø912/Ø632 ×78" mean exactly? A: Outside diameter 912 mm, inside diameter (bore) 632 mm, and 78 mm face height. The wall is (912−632)/2 = 140 mm.

Q: Can you supply 625 rings to NACE? A: Yes, Inconel 625 is qualified to NACE MR0175 in the appropriate condition; state the NACE requirement on the RFQ so the heat and hardness are controlled.

Q: Forged ring or machined disc for my flange? A: If the part is annular (a ring, collar or hollow cylinder), a rolled ring forging is the efficient route; if it is a solid faced disc or blind flange, a machined forged disc is usually shorter.

Q: How heavy is a 912/632×78 ring in 625? A: Roughly the volume of the annulus (π/4·(0.912²−0.632²)·0.078 m³ ≈ 0.026 m³) × density ~8.44 g/cm³ ≈ 220 kg before machining — use the weight calculator for exact planning.