Standards & threads

Finished boltASTM F593Alloy Group 1 · 304L · CW · inch series

Specify 304L explicitly rather than Group 1 alone. Scope: nominal 1/4–1-1/2 in.; this is not a metric specification. Identify the exact alloy, condition and edition.

A low-carbon material certificate and final cold-worked bolt properties are separate checks.

Raw material specificationASTM A276/A276M / ASTM A479/A479MUNS S30403

S30403 · 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

Select head width s, height k and thread length b. These are dimensional references here; other alloys do not automatically conform to the full steel/stainless product standard. Fine-pitch geometry needs a separate drawing or applicable standard.

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

State diameter × pitch and external tolerance class, e.g. M12 × 1.75–6g. Fine pitch must be written explicitly; 6g is a thread tolerance, not a strength grade.

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.

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.

Thread coverage
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

Material certificate

MTC · EN 10204 3.1 included

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

Low-carbon identity

S30403 and any explicit 304 / 304L dual-certification requirement.

Sets the chemistry evidence required on the certificate.

Thermal context

Relevant welding / heating history and specified final condition.

Explains the selection basis without assuming the bolt will be welded.

Bolt strength

Required fastener standard, property class and acceptance tests.

Keeps low carbon separate from mechanical-class selection.

Commercial terms

Indicative terms; confirmed in your quotation.

Typical MOQ

10pieces

Subject to product and material review.

Conditions

MOQ is typically 10 pieces, subject to product, material and manufacturing-route review.

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

How do I make sure a Group 1 bolt order retains 304L?

Write 304L and UNS S30403 on the order rather than Group 1 alone. Request material records that support the low-carbon identity, then specify the required finished condition and mechanical acceptance separately.

Does a 304L material certificate establish the bolt strength?

It supports the material identity and the properties actually reported for that product form. The final bolt’s cold-worked condition, diameter and applicable fastener requirements determine the required finished-part evidence.

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 304L bolt

Send a drawing or add your dimensions and quantity.

Continue to enquiry ↗
Combine several products in one enquiry
304L hex boltsEnquire ↗
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