Duplex 2205 12-point flange bolts
ASME B18.2.5MASTM A276
Duplex 2205 twelve-point flange bolts suit connections with restricted tool indexing and a compact head envelope. The material contributes duplex strength and chloride-corrosion resistance; 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 and quenched
EN 10204 3.1 MTC + heat-number traceability
Which standard is on your order?
Raw Material Specifications
Finished-Bolt Specifications
Threads · Metric
Threads · Inch
Dimension Reference
Heat Treatment
Solution annealed and rapidly cooledSolution annealing followed by rapid cooling controls harmful precipitates and preserves the ferrite–austenite structure.
What we can make in Duplex 2205
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 and quenched
- Inspection
- Thread gauges · Head and shank dimensions
Manufacturing route
CNC machining suits samples; a volume heading or forging route must preserve duplex phase balance through forming and final thermal processing.
Heat treatment & final condition
Solution treatment and cooling control the duplex structure. Subsequent processing must preserve the ordered corrosion and mechanical condition.
Finished geometry
Head geometry, bearing face, shank and thread fit are checked after the final machining and thermal operations.
Where Duplex 2205 fits — and what matters
Offshore & Marine
Deck-equipment brackets and marine pump skidsDuplex 2205 12-point flange bolts fasten deck-equipment brackets and marine pump skids where a 12-point socket gives useful indexing around restricted equipment access. The flange supports the loaded head seat. The assembled contact is exposed to saltwater, deposits and neighbouring metals.
Water Treatment & Desalination
Membrane-skid and pump supportsDuplex 2205 12-point flange bolts fasten membrane-skid and pump supports where a 12-point socket gives useful indexing around restricted equipment access. The flange supports the loaded head seat. The water stream, cleaning cycle and retained liquid define exposure at the installed part.
Oil & Gas
Utility skids and instrument supportsDuplex 2205 12-point flange bolts fasten utility skids and instrument supports where a 12-point socket gives useful indexing around restricted equipment access. The flange supports the loaded head seat. Utility connections and pressure-boundary parts have separate acceptance requirements on the equipment drawing.
Same 12-point flange bolt. Different material priorities.
Duplex 2205 material dataInconel 625
Solid-solution strength and resistance to aggressive process liquids.
- Connection priority
- Clamp load through a compact head envelope
- Annealed or solution-annealed 625
- The delivery condition affects strength and high-temperature response. Keep the specified condition with the component’s mechanical acceptance; 718-style aging is not the strengthening route for 625. Include liquid retained at the compact twelve-point drive and flange-bearing surface in the exposure description.
Super Duplex 2507
Super-duplex strength and resistance to chloride pitting.
- Connection priority
- Clamp load through a compact head envelope
- Final duplex structure
- S32750 chemistry and final solution treatment belong together. Forming, section size and cooling affect the structure represented by the mechanical and corrosion records. Include liquid retained at the compact twelve-point drive and flange-bearing surface in the exposure description.
Monel K-500
Age-hardened strength in the nickel–copper alloy family.
- Connection priority
- Clamp load through a compact head envelope
- Strength and hydrogen exposure
- K-500 gains strength through aging. Cathodic protection, hydrogen exposure and the ordered condition need joint consideration in highly loaded marine components. Include liquid retained at the compact twelve-point drive and flange-bearing surface in the exposure description.
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
- S31803 / S32205 · heat number · ordered condition
- Final-part acceptance
- Final condition and any ordered phase-balance, corrosion or impact testing.
- Dimensional record
- Thread gauges · Head and shank dimensions
- Traceability
- EN 10204 3.1 material certificate · production lot · identified packing
Build your Duplex 2205 12-point flange bolt enquiry
Questions about Duplex 2205 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.