254 SMO Long-shank hex head bolts
ISO 4014ASTM A276
254 SMO long-shank hex bolts carry the grip through a plain section while providing high-molybdenum austenitic resistance to chloride exposure. Grip length and thread runout locate the loaded interfaces along the extended shank.
- MOQ
- 100PCS
- Samples · typical
- ~20 days
- Production · typical
- 25–35 days
- Heat treatment
- Solution annealed
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 annealedSolution annealing and rapid cooling retain alloying elements in solution and restore the specified corrosion-resistant condition.
What we can make in 254 SMO
Plain grip section
Use across thick equipment flanges, spacers and mounting stacks where the grip requires a continuous plain shank. The grip length keeps the threaded transition beyond the intended bearing or shear section.
Threaded end
Allow enough usable thread beyond the stack for the nut, washer and tightening travel. Too little thread can leave the nut bottomed on the plain shank before the joint is clamped.
Long shank vs shoulder screw
For a pivot or locating bore, specify the actual shank diameter tolerance and surface finish. A long-shank bolt provides grip length; a shoulder-screw fit requires separate control of the locating surface.
- Head
- External hex
- Shank
- Extended plain length
- Length basis
- Under head
- Threads
- Metric · UNC · UNF · UNJ
- Final condition
- Solution 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 final annealed or specified strengthened condition is linked to the lot; an aging treatment is not assumed for a solid-solution alloy.
Finished geometry
Head geometry, bearing face, shank and thread fit are checked after the final machining and thermal operations.
Where 254 SMO fits — and what matters
Offshore & Marine
Deck-equipment brackets and marine pump skids254 SMO long-shank hex head bolts pass through the deeper grip of deck-equipment brackets and marine pump skids; the extended plain shank locates the joint before the nut takes up the thread. The assembled contact is exposed to saltwater, deposits and neighbouring metals.
Water Treatment & Desalination
Membrane-skid and pump supports254 SMO long-shank hex head bolts pass through the deeper grip of membrane-skid and pump supports; the extended plain shank locates the joint before the nut takes up the thread. The water stream, cleaning cycle and retained liquid define exposure at the installed part.
Oil & Gas
Utility skids and instrument supports254 SMO long-shank hex head bolts pass through the deeper grip of utility skids and instrument supports; the extended plain shank locates the joint before the nut takes up the thread. Utility connections and pressure-boundary parts have separate acceptance requirements on the equipment drawing.
Same long-shank hex head bolt. Different material priorities.
254 SMO material dataInconel 625
Solid-solution strength and resistance to aggressive process liquids.
- Connection priority
- Tension and thermal expansion along the extended shank
- 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 long grip inside the joint and the under-head seat in the exposure description.
Super Duplex 2507
Super-duplex strength and resistance to chloride pitting.
- Connection priority
- Tension and thermal expansion along the extended shank
- 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 long grip inside the joint and the under-head seat in the exposure description.
Monel K-500
Age-hardened strength in the nickel–copper alloy family.
- Connection priority
- Tension and thermal expansion along the extended shank
- 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 long grip inside the joint and the under-head seat 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
- UNS S31254 · 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 254 SMO long-shank hex head bolt enquiry
Questions about 254 SMO long-shank hex head bolts
Why is total length insufficient for a long-shank bolt?
Two bolts of the same total length can put the thread runout in different places. The joint needs a defined grip length so its bearing or shear interface meets the intended shank section.