Property Class 12.9 Steel Miniature Captive Pan-Head Screws 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.
Material page for miniature captive pan-head screws in Property Class 12.9 Steel (ISO 898-1 property class 12.9). The sizes below are the ones we supply; there is no published dimensional standard for this article, so the table rather than a standard number is what to quote. Corrosion behaviour is requires plating or black-oxide protection and the service range is commonly limited to approx. +300 °C; confirm against the coating and the load.
Why Choose Property Class 12.9 Steel for Miniature Captive Pan-Head Screws
The highest common strength class, for high-load machine assembly. For miniature captive pan-head screws, 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 miniature captive pan-head screws 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.
Comparable Grades
For Miniature Captive Pan-Head Screws, class 8.8 is the comparable strength step. Move up when the joint preload approaches the proof load of the current class; move down when the joint is over-specified. For corrosion-critical service, switch to stainless A2 or A4.
Sizes of Miniature Captive Pan-Head Screws Available in Property Class 12.9 Steel
| Thread size | Length options (mm) | Head diameter (mm) | Captive length (mm) | Under-head length (mm) | Maximum torque (N·m) |
|---|
| M1.4 | 4 / 5 / 6 / 8 / 10 | 2.0 | 2.0 | 0.5 | 0.03 |
| M1.6 | 4 / 5 / 6 / 8 / 10 | | | | |
| M1.7 | 4 / 5 / 6 / 8 / 10 | | | | |
| M2.0 | 4 / 5 / 6 / 8 / 10 | | | | |
| M2.5 | 4 / 5 / 6 / 8 / 10 | | | | |
| M2.6 | 4 / 5 / 6 / 8 / 10 | 4.0 | | 1.8 | 0.16 |
Dimensions are independent of the material: every size above is available in Property Class 12.9 Steel.
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 Miniature Captive Pan-Head Screws are used, and what decides the specification in each case. Stocked from M1.4 to M2.6.
Industries that specify Miniature Captive Pan-Head Screws
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Precision housings
Captive screws keep miniature covers together during service.
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Instrumentation
Small captive heads prevent loose hardware from entering a mechanism.
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Electronics repair
Short under-head shanks hold the screw in a thin cover.
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Production fixtures
Repeatable access is faster when the screw cannot fall away.
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Maintenance & MRO
Stocked replacements matched to an existing property class, thread and finish.
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Food, pharma & cleanroom
Stainless assemblies that are washed down, where the finish matters as much as the strength.
Typical applications
- retaining a miniature screw in a removable panel
- selecting the captive shank for panel thickness
- limiting torque on the smallest head and thread
- keeping the screw with the cover during service
- 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.
- 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 use a captive under-head length that binds the panel before the thread is engaged.
- 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 Miniature Captive Pan-Head Screws are used, how to specify them, and the cases they are wrong for
