Incoloy 800HT 12-point flange bolts
ASME B18.2.5MASTM B408
Incoloy 800HT twelve-point flange bolts suit connections with restricted tool indexing and a compact head envelope. The material contributes tightly controlled carbon and Al + Ti for creep duty; the drive profile and flange transmit installation torque and clamp load.
- MOQ
- 100PCS
- Samples · typical
- ~20 days
- Production · typical
- 25–35 days
- Heat treatment
- Solution annealed (≥1149°C / 2100°F)
EN 10204 3.1 MTC + heat-number traceability
Which standard is on your order?
Raw Material Specifications
Threads · Metric
Threads · Inch
Dimension Reference
Heat Treatment
Solution annealedThe specified solution treatment develops the controlled grain structure needed for sustained high-temperature creep duty.
What we can make in Alloy 800HT
Fully threaded / Partially threaded
The difference is the plain shank. Fully threaded bolts have threads along the shank up to the head transition; partially threaded bolts retain an unthreaded grip section beneath the flange.
External head / Internal recess
The difference is where the tool engages. An external 12-point head is gripped around its outside by a matching socket. An internal spline recess is driven by a bit inserted into the head. These are different drive structures and should not be specified interchangeably.
- Drive
- External 12-point
- Bearing
- Integral flange
- Length basis
- Under flange
- Threads
- Metric · UNC · UNF · UNJ
- Final condition
- Solution annealed (≥1149°C / 2100°F)
- Inspection
- Thread gauges · Head and shank dimensions
Manufacturing route
CNC machining suits samples and small lots. Cold heading or hot forging is selected for volume production according to alloy formability, head section and size.
Heat treatment & final condition
Solution annealing at a minimum of 1149°C (2100°F) establishes the coarse-grain condition used for creep resistance. The heat-treatment record and grain-size result identify this delivery state.
Finished geometry
Head geometry, bearing face, shank and thread fit are checked after the final machining and thermal operations.
Where 800HT fits — and what matters
Furnaces & Heat Treatment
Heat-treatment fixturesIncoloy 800HT 12-point flange bolts fasten heat-treatment fixtures where a 12-point socket gives useful indexing around restricted equipment access. The flange supports the loaded head seat. Hot dwell, thermal expansion and repeated furnace cycles set the working load.
Power & Turbines
Boiler-duct supports and hot auxiliary bracketsIncoloy 800HT 12-point flange bolts fasten boiler-duct supports and hot auxiliary brackets where a 12-point socket gives useful indexing around restricted equipment access. The flange supports the loaded head seat. Hot dwell and start-stop expansion act on the supported or moving component.
Chemical Processing
Reformer tube-support and heater fixturesIncoloy 800HT 12-point flange bolts fasten reformer tube-support and heater fixtures where a 12-point socket gives useful indexing around restricted equipment access. The flange supports the loaded head seat. These parts work in the heated equipment zone, where sustained loading and thermal expansion govern their section and clearance.
Same 12-point flange bolt. Different material priorities.
Incoloy 800HT material dataIncoloy 800
UNS N08800- Carbon
- ≤0.10%
- What changes
- General heat and oxidation resistance; no grain-size requirement in the family comparison.
Incoloy 800H
UNS N08810- Carbon
- 0.05–0.10%
- What changes
- Controlled carbon and coarse-grain condition for creep and stress-rupture duty.
Incoloy 800HT
UNS N08811 · Current grade- Carbon
- 0.06–0.10%
- What changes
- Tighter carbon and Al + Ti control (0.85–1.20%), with solution treatment and coarse grain for creep duty.
From drawing to documented delivery
- 01Drawing & BOMForm, dimensions and quantity
- 02Material & formingGrade, heat and manufacturing route
- 03Final inspectionGeometry, threads and ordered tests
- 04Documents & dispatchLot records and identified packing
Order documents
- Material identity
- UNS N08811 · heat number · ordered condition
- Final-part acceptance
- UNS grade, carbon and alloy chemistry, solution-treatment record and ordered grain-size evidence.
- Dimensional record
- Thread gauges · Head and shank dimensions
- Traceability
- EN 10204 3.1 material certificate · production lot · identified packing
Build your 800HT 12-point flange bolt enquiry
Questions about 800HT 12-point flange bolts
Does a twelve-point head establish a higher bolt strength?
The drive profile provides tool access. Strength comes from the specified alloy, final condition and section; head engagement and flange bearing still have to transmit the installation and service loads.