Typical MOQ
10pieces
Subject to product and material review.
Conditions
MOQ is typically 10 pieces, subject to product, material and manufacturing-route review.
321 Hex Bolts — ASTM F593
Material321Change · 45 grades
- Material
- 321 · UNS S32100 · Stainless steel 321
- Material focus
- Resistance to sensitization · titanium-stabilized
- Common applications
- Welded equipment · hot-process components
- Main elementslimits · wt.%
- Cr 17–19%
- Ni 9–12%
- Ti 5×(C+N)–0.70%
- C ≤0.08%
Standards & threads
Finished boltASTM F593Alloy Group 3 · 321 · CW · inch series
Specify titanium-stabilized 321 rather than Group 3 alone. Scope: nominal 1/4–1-1/2 in.; this is not a metric specification. Identify the exact alloy, condition and edition.
For a high-temperature inch route, F2281 Type II lists 321; select its condition separately from F593.
Raw material specificationASTM A276/A276M / ASTM A479/A479MUNS S32100
S32100 · stainless bar
Select the stock-form specification and required condition. These are bar specifications, not finished-bolt strength classes.
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.
Heat treatment / conditionAnnealed
Reference specimen: Sheet test samples
1093°C (2000°F), air cooled.
Reference condition from material data. The ordered condition is agreed in your quotation.
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
Stabilized grade
S32100 and the required stabilization / heat-treatment condition.
Distinguishes titanium-stabilized 321 from 347 or low-carbon alternatives.
Heating history
Service temperature, exposure duration and relevant fabrication heating.
Provides the basis for reviewing the intended stabilized condition.
Part acceptance
S32100; A276/A479 bar; F593 Group 3 CW for an inch order within scope, or a separate acceptance plan.
Separates the bar certificate from finished-bolt condition and acceptance.
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 F593 Group 3 distinguish 321 from 347?
The group includes both grades. State 321 and S32100 explicitly to retain titanium-stabilized material, with the required condition and edition. A shared fastener group does not make a change to 347 automatic.
Which route should I review for high-temperature 321 bolting?
F2281 Type II lists 321 as a separate high-temperature inch route. Select its required condition and tests rather than carrying over a F593 callout unchanged. Provide the thermal duty and final material-condition requirements with the drawing.
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 321 bolt
Send a drawing or add your dimensions and quantity.
Continue to enquiry ↗
Combine several products in one enquiry
321 hex boltsEnquire ↗