Typical MOQ
10pieces
Subject to product and material review.
Conditions
MOQ is typically 10 pieces, subject to product, material and manufacturing-route review.
254 SMO Hex Bolts
Material254 SMOChange · 45 grades
- Material
- 254 SMO · UNS S31254
- Material focus
- Chloride corrosion resistance
- Common applications
- Seawater equipment · chemical-process equipment
- Main elementsComposition limits · wt.%
- Cr 19.5–20.5%
- Ni 17.5–18.5%
- Mo 6.0–6.5%
- N 0.18–0.25%
Standards & threads
Finished boltDrawing-defined acceptanceNo grade-specific finished-bolt specification was established in the reviewed sources.
Define the finished-bolt strength / hardness requirements and any pitting or crevice-corrosion test with temperature, duration and acceptance limit.
S31254 is a super-austenitic grade. Do not assign the duplex A1082 route solely because the alloy is used in chloride service.
Raw material specificationASTM A276/A276M / ASTM A479/A479MUNS S31254
S31254 · stainless bar
State the exact 6Mo grade and solution-treated condition. A240 flat-product data is not bar acceptance.
Dimensions · metricISO 4014 / ISO 4017Coarse pitch · partial-thread bolts / full-thread hex screws
Dimensions · inchASME B18.2.1Inch hex bolts / hex cap screws
Select the bolt or cap-screw pattern, head dimensions and thread length. Hex and heavy hex are different choices.
Threads · metricISO 261 / ISO 965-1Metric M · pitch plan and tolerance system
Threads · UNC / UNFASME B1.1Unified inch · coarse / fine series
State diameter, TPI, series and external class: e.g. 1/2-13 UNC-2A or 1/2-20 UNF-2A. Select 2A / 3A with the mating-thread fit; UNC and UNF do not mate.
Mechanical testing ASTM F606/F606M
Mechanical test methods for fasteners; select applicable tensile, yield and hardness tests. This standard supplies methods, not a material grade or pass/fail limits. Define those limits and sampling in the part specification.
Test-method reference ↗Sources & editions Reviewed 2026-10-19
Historical samples support the stated grade coverage. The ordered edition controls the full requirements.
Preview your dimensions
Example dimensions, not a stock size.
Simplified right-hand thread appearance. No tolerance, fit or standard compliance is simulated.
Head dimensions · optional
Head proportions are illustrative: s = 1.5d, k = 0.625d. They are not standard-table values and will not be submitted as specified dimensions.
Quality documents
Heat number traceability
Every delivery traceable by heat number
Mechanical testing
Included with every delivery
Thread inspection
GO / NO-GO gauging · sampled inspection
Methods, sampling and acceptance criteria follow the agreed specification. PMI, third-party inspection and additional records are agreed separately.
Before production and at delivery
During quotation, a redacted certificate from a previous order can show the document format and recorded tests. It is a historical example, not certification of this product or a new order. Shipment documents must correspond to the material and batch actually supplied.
How to read a historical certificate sample ↗Prepare your enquiry
Send a drawing and quantity.
No drawing? Use these details.
- Size
- d × L Diameter × under-head length
- Quantity
- Pieces Required quantity per size
- Thread
- Metric / UNC / UNF Pitch or TPI + thread class
- Coverage
- Full / Partial For partial, include threaded length
Full material checklist
Chloride / crevice basis
Medium, concentration, temperature and crevice or deposit conditions.
Focuses selection on the local exposure around the fastener.
Material identity
S31254, product-form specification and solution-annealed condition.
Avoids treating all 6Mo or duplex grades as equivalent.
Strength and tests
Finished-bolt properties and any specified corrosion testing.
The corrosion-focused designation does not define a fastener property class.
Commercial terms
Indicative terms; confirmed in your quotation.
Sample review
~20days
Freight, import duties and taxes are separate.
Conditions
Samples are typically reviewed on an approximately 20-day basis. BYBOLT may cover agreed sample manufacturing; buyer freight, import duties and taxes remain separate.
Production review
25–35days
Urgent requirements can be discussed.
Conditions
Regular production is commonly reviewed on a 25–35 day basis. Urgent requirements can be discussed against the complete specification.
Typical deposit
30%
T/T or LianLian. Balance before dispatch.
Conditions
Payment can be arranged by T/T or LianLian. A typical order uses a 30% deposit, with the balance completed before dispatch.
Technical help
Does the duplex A1082 route automatically cover 254 SMO bolts?
S31254 is super-austenitic stainless steel, not duplex. The reviewed duplex entries do not establish a 254 SMO bolting route. Use the verified A276/A479 bar references and specify the finished-bolt mechanical acceptance separately.
What should I specify for a 254 SMO chloride-service enquiry?
Give chloride exposure, temperature and crevice conditions, together with the required solution-treated condition. For a specified pitting or crevice test, name the method, duration, temperature and acceptance limits in the inspection scope.
Read a thread designation Metric / UNC / UNF
M12 × 1.75–6g12 mm diameter · 1.75 mm pitch · external class 6g
1/2-13 UNC-2A1/2 inch · 13 TPI · coarse · external class 2A
1/2-20 UNF-2A1/2 inch · 20 TPI · fine · external class 2A
Examples explain designations, not available sizes. Specify fine pitch explicitly. UNC and UNF do not mate; full or partial threading is a separate choice.
Thread classes and inspection ↗Related material guides
Download the PO and receiving checklist (PDF)
Guides for your enquiry
Specify your 254 SMO bolt
Send a drawing or add your dimensions and quantity.
Continue to enquiry ↗
Combine several products in one enquiry
254 SMO hex boltsEnquire ↗