UNS N08800

Incoloy 800 12-point flange bolts

ASME B18.2.5MASTM B408

Incoloy 800 twelve-point flange bolts suit connections with restricted tool indexing and a compact head envelope. The material contributes heat and oxidation resistance for thermal equipment; the drive profile and flange transmit installation torque and clamp load.

MOQ
100PCS
Samples · typical
~20 days
Production · typical
25–35 days
Heat treatment
Annealed

EN 10204 3.1 MTC + heat-number traceability

Upload drawing

Which standard is on your order?

Raw Material Specifications

Threads · Metric

Threads · Inch

Dimension Reference

Heat Treatment

Annealed

Annealing reduces work hardening and restores ductility for the specified supplied condition.

What we can make in Alloy 800

Fully threaded and partially threaded twelve-point flange bolts, side views

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 twelve-point head compared with internal spline recess

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
Annealed
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

The ordered annealed or solution-treated state is retained in the lot record; forming and machining do not replace the specified thermal condition.

Finished geometry

Head geometry, bearing face, shank and thread fit are checked after the final machining and thermal operations.

Where 800 fits — and what matters

Heat-treatment workshop with horizontal furnaces, green pipes and a blue motor

Furnaces & Heat Treatment

Heat-treatment fixtures

Incoloy 800 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.

Socket envelope · flange seat · tightening access
Furnaces & Heat Treatment fasteners
Technician inspecting blade rows beneath a large turbine rotor

Power & Turbines

Boiler-duct supports and hot auxiliary brackets

Incoloy 800 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.

Socket envelope · flange seat · tightening access
Power & Turbines fasteners
Silver distillation columns with access ladders and yellow service platforms

Chemical Processing

Reformer tube-support and heater fixtures

Incoloy 800 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.

Socket envelope · flange seat · tightening access
Chemical Processing fasteners

Same 12-point flange bolt. Different material priorities.

Incoloy 800 material data

Incoloy 800

UNS N08800 · Current grade
Carbon
≤0.10%
What changes
General heat and oxidation resistance; no grain-size requirement in the family comparison.

Incoloy 800HT

UNS N08811
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.
Incoloy 800HT 12-point flange bolts

From drawing to documented delivery

Heat treatment
Heat treatment
CNC machining
CNC machining
Rockwell hardness testing
Rockwell hardness testing
Wooden-crate packing
Wooden-crate packing
  1. 01Drawing & BOMForm, dimensions and quantity
  2. 02Material & formingGrade, heat and manufacturing route
  3. 03Final inspectionGeometry, threads and ordered tests
  4. 04Documents & dispatchLot records and identified packing

Order documents

Material identity
UNS N08800 · heat number · ordered condition
Final-part acceptance
Grade chemistry, supplied condition and ordered mechanical requirements.
Dimensional record
Thread gauges · Head and shank dimensions
Traceability
EN 10204 3.1 material certificate · production lot · identified packing

Build your 800 12-point flange bolt enquiry

QUOTE LIST ITEMIncoloy 800 12-point flange bolts; UNS N08800; Full thread

Questions about 800 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.

Technical references & photo credits