Specifications
Surface Treatments
Certifications
- ISO 9001 - 2015 Certified
- PED 2014/68/EC
- NACE MR0175/ISO 15156-2
- NORSOK M-650
- DFAR
- MERKBLATT AD 2000 W2/W7/W10
Incoloy 800H Round Bar
Incoloy 800H round bar (UNS N08810, Werkstoff 1.4876) is supplied to ASTM B408 / ASME SB-408 in OD 8 mm to 250 mm from qualified Special Metals, VDM, Outokumpu and ATI mill sources, with the smaller diameters (8 to 50 mm) produced by cold-drawing for tight tolerance and high surface quality and the larger diameters (50 to 250 mm) produced by hot-rolling and machined finish. Solution annealed at 2050 deg F (1121 deg C) and quench-cooled to lock in ASTM grain size 5 or coarser, this is the canonical feed-stock for in-house machining of valve stems, pump shafts, instrumentation parts, fastener blanks (stud bolts, hex bolts, nuts), reformer pigtail return-bends and pressure-vessel internals across the 800H envelope to design service of 815 deg C (1500 deg F). Each bar carries an EN 10204 type 3.1 mill certificate by default with heat-number chemistry per B408 ranges, solution-anneal cycle, room-temperature mechanical results per ASTM A370, hardness, grain-size verification per ASTM E112 and dimensional check; type 3.2 third-party witness from Lloyds Register, DNV, BV, SGS or TUV is supplied on call-out.
Round Bar Dimensions per ASTM B408
| Property | Range |
|---|---|
| Diameter range (cold-drawn) | 8 mm to 50 mm |
| Diameter range (hot-rolled) | 50 mm to 250 mm |
| Length | 3 m to 6 m standard; cut-to-length per PO |
| Diameter tolerance (cold-drawn h9) | per ASTM B408 paragraph 8 |
| Diameter tolerance (hot-rolled) | per ASTM B408 paragraph 8 |
| Surface finish (cold-drawn) | Bright, Ra typ. 0.4 to 0.8 micron |
| Surface finish (hot-rolled) | Black scale (default), peeled-turned or centerless-ground on call-out |
| Straightness | per ASTM B408 paragraph 9 |
Round Bar Manufacturing Route
- Mill source verification: Special Metals, VDM, Outokumpu or ATI. Verify mill 3.1 cert + chemistry + traceability.
- Hot-roll: Continuous-cast billet hot-rolled to OD on rolling mill at 1180 to 1200 deg C.
- Solution anneal: 2050 deg F + accelerated air-cool per B408.
- Pickle: Nitric-HF pickle removes scale on cold-drawn bar feedstock.
- Cold draw (small OD only): Multiple cold-draw passes to final OD with intermediate process-anneal.
- Centerless-grind / peel-turn: Larger hot-rolled bars peeled-turned or centerless-ground for tight tolerance and bright finish on call-out.
- Straighten: Multi-roll straightener to B408 paragraph 9.
- NDT: Eddy-current per ASTM E1606 (small OD) or ultrasonic per ASTM A388 (large OD).
- Cut + chamfer: Saw-cut to length, chamfer both ends.
- Marking: per ASTM B408 paragraph 12 - heat number, grade N08810, OD, mill mark, paint colour band per PFI ES-22.
Sizes Stocked and Lead Times
| Diameter band | Stock status | Lead time |
|---|---|---|
| 8 to 25 mm (cold-drawn) | Held in stock | 1 to 2 weeks |
| 30 to 60 mm (hot-rolled or cold-drawn) | Held in stock | 2 to 3 weeks |
| 70 to 150 mm (hot-rolled, peeled) | Held in stock | 3 to 4 weeks |
| 160 to 250 mm (hot-rolled, peeled or as-rolled) | Indent | 10 to 14 weeks |
Round Bar Inspection and Marking
- Eddy-current per ASTM E1606 on cold-drawn bar (8 to 50 mm OD).
- Ultrasonic per ASTM A388 on hot-rolled bar (50 mm OD and above).
- Tensile + yield + elongation per ASTM A370 - full-section coupon for bar below 50 mm OD, machined-section coupon for bar above 50 mm OD.
- Hardness per ASTM E18 - Rockwell B 70 to 90 in solution-annealed condition.
- Grain size per ASTM E112 on coupon per heat / lot. Acceptance: grain size 5 or coarser.
- Surface finish: profilometer check on cold-drawn bar (Ra typ. 0.4 to 0.8 micron).
- Marking: per ASTM B408 paragraph 12 - grade, OD, heat number, mill mark, paint colour band.
Typical Round Bar End-Uses
| End-use | OD range | Companion application |
|---|---|---|
| Fastener blank stock (stud bolts, hex bolts) | 8 to 100 mm | Fasteners |
| Valve stem / spindle | 20 to 200 mm | Machined components |
| Pump shaft | 50 to 250 mm | Machined components |
| Reformer pigtail return-bend stock | 50 to 150 mm | Reformer pigtails |
| Instrument tubing blank / lead-line | 8 to 25 mm | Seamless tube |
Companion Forms
800H round bar feeds into in-house machined components and fasteners, and into forged blanks for the B564 forging programme on larger sections. For parent specifications see chemical composition and mechanical properties. For high-temperature design stress curves, see the ASME design stress tables.
Engineering Guidance for Round Bar Specification
When specifying 800H round bar for downstream machining, the dominant decision factors are diameter, surface finish, and machining allowance. Cold-drawn bar from 8 mm to 50 mm OD delivers tight diameter tolerance (h9 typical) and a bright surface finish (Ra 0.4 to 0.8 micron) suitable for direct machining without skin removal. Hot-rolled bar from 50 mm OD upward is supplied with peeled-turned surface (skin removed by lathe) by default for valve-stem and pump-shaft feedstock; as-rolled black-scale finish is supplied only on call-out for parts that will be re-forged or hot-worked. Machining allowance per side should be confirmed against the project drawing: typical 1.5 mm per side on cold-drawn bar, 3 to 6 mm per side on hot-rolled bar to allow for surface peeling plus finish-machining cuts. For fastener blank stock (stud bolts, hex bolts), cold-drawn bar is preferred because the as-supplied finish is closer to the finished bolt OD and the heat-thread-thread-process route is simplified. For long-shaft parts (pump shafts, mixer shafts) above 1500 mm length, straightness per ASTM B408 paragraph 9 should be specified tighter than the standard envelope. The TorqBolt sales desk can run through these decisions on request.
Round Bar FAQ
Q. What surface finish do you supply on cold-drawn 800H bar?
Cold-drawn bar is supplied with a bright finish at Ra 0.4 to 0.8 micron from the cold-draw die. For tighter tolerance or finer finish, centerless-ground or polished bar (Ra below 0.4 micron) is available on call-out.
Q. Do you supply 800H bar with peeled-turned (PT) or skin-removed surface?
Yes. Hot-rolled bar above 50 mm OD is supplied peeled-turned to remove the as-rolled black scale and any sub-surface defects. PT finish is the default for valve-stem and pump-shaft feed-stock.
Q. What ASTM B408 grain-size requirement applies to bar above 100 mm OD?
ASTM B408 requires grain size 5 or coarser for 800H (UNS N08810). On bars above 100 mm OD, the central core may exhibit slightly coarser grain than the surface due to the slower cooling rate during solution-anneal quench. The acceptance is based on a coupon machined from the half-radius position, which is representative of the average grain size through the cross-section.
Q. Can you supply 800H bar with NACE MR0175 sour-service compliance?
Yes. 800H bar in the solution-annealed condition meets NACE MR0175 / ISO 15156 hardness limits (22 HRC max for Ni-Fe-Cr alloys, 237 HV equivalent). The bar is supplied with the NACE MR0175 compliance statement on the EN 10204 certificate.
Q. Do you cut 800H bar to length on order?
Yes. Standard length is 3 to 6 m mill-cut; cut-to-length per PO is supplied with +/- 1 mm cut tolerance on cold-saw or +/- 3 mm on band-saw cut. Both-end chamfer is supplied as standard.
Request a Quote on Incoloy 800H Round Bar
Send the project drawing or cut list, OD, length, surface finish (cold-drawn / peeled-turned / centerless-ground), tolerance class, certification class (3.1 or 3.2) and any PMI / NACE MR0175 / cut-to-length add-ons to our sales desk.
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