Bolt Grade Decoder

Inputs

Results

Decoded result
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Confidence
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Details

Segment breakdown
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Reference

Reference table
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Reference Table

InputDecoded result
8.8ISO metric property class 8.8: nominal tensile strength 800 MPa, yield ratio 0.8.
10.9ISO metric property class 10.9: nominal tensile strength 1000 MPa, yield ratio 0.9.
12.9ISO metric property class 12.9: nominal tensile strength 1200 MPa, yield ratio 0.9.
4.6ISO metric property class 4.6: nominal tensile strength 400 MPa, yield ratio 0.6.
5.8ISO metric property class 5.8: nominal tensile strength 500 MPa, yield ratio 0.8.

Code Structure

Bolt Grade Decoder splits the marking into recognized segments, explains what each segment means, and flags ambiguous or incomplete inputs.

How To Decode

  1. Enter the marking exactly as printed, including spaces, hyphens, suffixes, and units.
  2. Review the segment breakdown first, then compare candidates in the result table when more than one interpretation is possible.
  3. Use the cited standard or manufacturer datasheet before making safety, procurement, or compliance decisions.

Sources And Limits

ISO metric fastener property class conventions, SAE grade markings, ASTM references, and stainless fastener class guides; verified 2026-08-26.

Decode logic

  • Normalize the marking, parse the known tokens, then return the decoded meaning with confidence and source caveats.

FAQs

Can this decoder guarantee the final specification?

Bolt Grade Decoder explains the visible marking and highlights common meanings. Always confirm safety-critical or purchase decisions against the manufacturer data sheet, product label, and applicable local standard.

Why can one code have more than one meaning?

Many real-world markings are reused by different manufacturers, regions, packages, or standard systems. Use surrounding context such as package, size, voltage, country, and product family.

What is a good input example?

Use the complete visible marking, for example 8.8, including spaces, suffixes, and ratings when they are printed on the part.