Property Class 12.9 Steel Bicycle Spoke Nipples are supplied to ISO 898-1 property class 12.9. Corrosion behaviour is requires plating or black-oxide protection, the material is magnetic, and the usable service range is commonly limited to approx. +300 °C; confirm against the coating and the load. In practice this grade is the highest common strength class, for high-load machine assembly.
- Grade
- ISO 898-1 property class 12.9
- Corrosion resistance
- Requires plating or black-oxide protection
- Magnetic response
- Magnetic
- Service temperature
- commonly limited to approx. +300 °C; confirm against the coating and the load
Property values are typical for the grade. Certified mechanical test data is available on request for production orders.
Property Class 12.9 Steel (ISO 898-1 property class 12.9) is the highest common strength class, for high-load machine assembly. Specified on bicycle spoke nipples it determines the corrosion behaviour (requires plating or black-oxide protection) and the service temperature range (commonly limited to approx. +300 °C; confirm against the coating and the load); the dimensions are ours rather than a standard's, and are listed in full below.
Why Choose Property Class 12.9 Steel for Bicycle Spoke Nipples
The highest common strength class, for high-load machine assembly. For bicycle spoke nipples, this matters when requires plating or black-oxide protection is the primary requirement.
Mechanical & Physical Properties
| Grade designation | ISO 898-1 property class 12.9 |
|---|
| Magnetic response | Magnetic |
|---|
| Service temperature | commonly limited to approx. +300 °C; confirm against the coating and the load |
|---|
| Corrosion characteristic | Requires plating or black-oxide protection |
|---|
Corrosion Behavior in Service
Carbon and alloy steel bicycle spoke nipples require a coating for corrosion protection. Zinc plating (with or without passivation) is the most common; hot-dip galvanizing is used for outdoor structural service; black-oxide is mainly a tarnish-prevention finish for tool-room use.
Galvanic & Galling Considerations
For bicycle spoke nipples in steel, the dominant compatibility issue is hydrogen embrittlement at high property classes (10.9 and above) when electroplated. Plating must be followed by an appropriate baking treatment, or a non-electroplated finish (mechanical zinc, zinc flake) should be substituted.
Sizes of Bicycle Spoke Nipples Available in Property Class 12.9 Steel
| Form | Length options (mm) | Spoke thread families | Thread lock | Color options |
|---|
| Standard A | 12 / 14 / 14.5 / 16 | 1.8 / FG 2.0; 2.0 / FG 2.3; 2.34 / FG 2.6 | with or without thread-lock compound | black / blue / gold / green / purple / red / silver / turquoise |
| Standard B | 12 / 14 / 14.5 / 16 | 1.8 / FG 2.0; 2.0 / FG 2.3; 2.34 / FG 2.6 | with or without thread-lock compound | black / blue / gold / green / purple / red / silver / turquoise |
Dimensions are independent of the material: the table above lists the sizes supplied, and on this page every one of them is quoted in Property Class 12.9 Steel. The catalogue's default material column has been omitted here so it cannot be read as contradicting that.
Custom manufacturing · Made to drawing
Need this screw in a grade that is not listed?
Grade 12 9 Steel is one of the grades the catalog describes. Where the standard stops, the drawing takes over: fine pitches, left-hand threads, partial threading, and property classes above the catalogued grade where material and heat treatment allow. Made by cold heading or warm forging.
Minimum order from 2,000 pieces; samples within 7 days of drawing approval.
Custom screw manufacturingSend a drawing
Applications & Industries
Where Bicycle Spoke Nipples are used, and what decides the specification in each case. Stocked from Standard A to Standard B (nominal diameter).
Industries that specify Bicycle Spoke Nipples
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Wheel building
Spoke nipples tension and retain spokes at the rim.
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E-bike service
Brass nipples are preferred in the supplied guidance for higher service duty.
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Performance wheels
Aluminum colors and thread-lock options support the wheel specification.
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Bicycle repair
Length and spoke-thread family must match the spoke.
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Steel fabrication
Bolted connections in frames, enclosures, walkways and weldments, on the bench and on site.
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Energy & infrastructure
Tower, pipework, switchgear and plant fixings specified for long service life and inspectable joints.
Typical applications
- tensioning a spoke through a compatible nipple thread
- choosing 12–16 mm length for the rim and spoke
- selecting aluminum for weight or brass for e-bike duty
- using the supplied thread-lock and color options
- clamping two machined faces to a calculated preload
- bolting brackets, motors and gearboxes to a frame
Service conditions to specify against
- Marine and coastal
- Available in A4 (316) stainless for chloride exposure — coastal structures, pool halls, water treatment and deck hardware, where A2 will eventually pit.
- High load
- Supplied in ISO 898-1 property classes, so the joint can be designed to a stated proof load and tightened to a calculated torque rather than by feel.
- Vibration
- Specified where cyclic load would loosen a plain nut or screw — rotating plant, rail, mobile equipment and anything that is not re-torqued in service.
- Torque and preload
- The joint is designed around bolt tension, so lubrication, coating and the friction coefficient all change the torque figure — state them together.
Where to use something else
- Do not mix spoke thread families; a nipple that starts on the spoke can still have the wrong thread engagement.
- Do not use a machine thread into unthreaded sheet or timber; use a tapping screw, rivet nut or insert made for that parent material.
Full application guide: where Bicycle Spoke Nipples are used, how to specify them, and the cases they are wrong for
