Fastener Guide / Technical Reference

Metric 8.8 vs 10.9 vs 12.9

The three metric classes that dominate machinery catalogs, side by side. The class number is stamped on the head with the maker mark.

Last reviewed 2026-09-10 · Governing standard: ISO 898-1:2013; ISO 898-2:2022 · reference FG-FE5C03 · Report an error on this sheet

ISO 898-1 comparison

8.810.912.9
Tensile Rm (min)800 / 830 MPa*1040 MPa1220 MPa
Yield (min)640 / 660 MPa*940 MPa1100 MPa
Proof stress580 / 600 MPa*830 MPa970 MPa
Hardness250-320 / 255-335 HV*320 - 380 HV385 - 435 HV
Matching nutClass 8Class 10Class 12
Typical productHex bolts and screwsHex and flange boltsSocket head cap screws

* up to M16 / over M16. Governing standards: ISO 898-1:2013; ISO 898-2:2022. Editions shown are the latest confirmed as of September 2026. The drawing and the governing standard always take

These tables carry the same figures as the printed sheet below.

The printed sheet

Metric 8.8 vs 10.9 vs 12.9

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Text version of this sheet

ISO 898-1 · classes 8.8, 10.9 and 12.9 compared

What it is

FIELD IDENTIFICATION

The three metric classes that dominate machinery catalogs, side by side. The class number is

stamped on the head with the maker mark.

MFG

MFG

8.8

10.9

12.9

8.8

10.9

12.9 socket

Class number stamped on the head

ISO 898-1 comparison

8.8

10.9

12.9

Tensile Rm (min)

800 / 830 MPa*

1040 MPa

1220 MPa

Yield (min)

640 / 660 MPa*

940 MPa

1100 MPa

Proof stress

580 / 600 MPa*

830 MPa

970 MPa

Hardness

250-320 / 255-335 HV*

320 - 380 HV

385 - 435 HV

Matching nut

Class 8

Class 10

Class 12

Typical product

Hex bolts and screws

Hex and flange bolts

Socket head cap screws

* up to M16 / over M16.

Governing standards: ISO 898-1:2013; ISO 898-2:2022. Editions shown are the latest confirmed as of September 2026. The drawing and the governing standard always take

precedence over this sheet.

torquing any fastener. Verify the current governing standard, project documents, OEM requirements, size, thread, coating and lot certification. To the fullest extent permitted by law, The Fastener App disclaims liability

arising from reliance on this reference.

Fastener Guide reference FG-FE5C03 · thefastenerapp.com/fastener-guide/technical-reference/metric-8-8-vs-10-9-vs-12-9 · © The Fastener App. Reference only — verify the current governing standard, drawing and manufacturer data before specifying or installing.

Related sheets

← Metric Property Class 12.9ISO 898-2 Metric Nut Classes →

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See what every customer buys from you

Every account gets a category chart: share of dollars, share of times ordered and share of pieces. Your reps see what each customer buys from you, and the categories they are buying somewhere else stand out.

Share of dollars

Fasteners37%$69,879
Electrical10%$19,152
Fleet and Automotive7%$12,293
Hardware and Building Supplies5%$10,243
Tools and Equipment5%$9,811
Cutting Tools and Metalworking5%$9,740
Plumbing5%$8,865
All other25%$46,410

Share of times ordered

Fasteners44%355
Electrical12%94
Fleet and Automotive7%53
Tools and Equipment6%48
Cutting Tools and Metalworking4%36
Pneumatics4%34
Hardware and Building Supplies4%33
All other20%162

Share of pieces

Fasteners75%486,316
Fleet and Automotive6%38,905
Electrical5%31,100
Hardware and Building Supplies3%19,775
Sealing3%17,704
Abrasives3%17,251
General MRO2%16,133
All other4%23,770

Sample report from our demo store.

Sales rep territory management

The time planner splits each rep’s month by how much every customer spends. A customer that is 20% of the rep’s business gets about 35 hours a month, about 8 hours a week, and the rep’s week is laid out for them.

Share of the rep’s business

Summit Precast LLC20.2%
Brunswick Galvanizing Inc.14.6%
Talleyrand Signs LLC8.0%
Mayport Tool & Die Inc.7.8%
Eagle Mechanical LLC7.2%
Premier Electric Group5.9%
Tallahassee Packaging LLC3.7%
Coastal Maintenance Group3.3%
All others (64 customers)29.4%

Time each customer deserves

CustomerHours a monthHours a week
Summit Precast LLC35.08.1
Brunswick Galvanizing Inc.25.35.8
Talleyrand Signs LLC13.93.2
Mayport Tool & Die Inc.13.53.1
Eagle Mechanical LLC12.52.9
Premier Electric Group10.22.4
Tallahassee Packaging LLC6.41.5
Coastal Maintenance Group5.71.3
All others (64 customers)51.011.8

Sample plan from our demo store: 173 hours a month, all selling time.

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