Mechanical properties, corrosion behaviour and the full dimensional range for this grade.
Property Class 12.9 Steel All-Metal Lock Nuts 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.
Hidden Deck Fasteners Sourcing: Manufacturing, Types & Material Compatibility
Property Class 12.9 Steel All-Metal Lock Nuts are supplied to ISO 7042 / DIN 980. The grade provides requires plating or black-oxide protection and is magnetic; the practical service range is commonly limited to approx. +300 °C; confirm against the coating and the load. Property data, grade comparison and the full size table follow.
Why Choose Property Class 12.9 Steel for All-Metal Lock Nuts
The highest common strength class, for high-load machine assembly. For all-metal lock nuts, 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 all-metal lock nuts 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 all-metal lock nuts 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 All-Metal Lock Nuts Available in Property Class 12.9 Steel
Size
Pitch (mm)
Width across flats s (mm)
Nut height m (mm)
Reference standard
Notes
M5
0.8
8.0
6.0
ISO 7042 / DIN 980
Deformed-top locking, high-temperature capable
M6
1.0
10.0
7.0
ISO 7042 / DIN 980
Deformed-top locking, high-temperature capable
M8
1.25
13.0
9.0
ISO 7042 / DIN 980
Deformed-top locking, high-temperature capable
M10
1.5
16.0
11.0
ISO 7042 / DIN 980
Deformed-top locking, high-temperature capable
M12
1.75
18.0
13.0
ISO 7042 / DIN 980
Deformed-top locking, high-temperature capable
M14
2.0
21.0
15.0
ISO 7042 / DIN 980
Deformed-top locking, high-temperature capable
M16
2.0
24.0
17.0
ISO 7042 / DIN 980
Deformed-top locking, high-temperature capable
M18
2.5
27.0
19.0
ISO 7042 / DIN 980
Deformed-top locking, high-temperature capable
M20
2.5
30.0
21.0
ISO 7042 / DIN 980
Deformed-top locking, high-temperature capable
M24
3.0
36.0
24.0
ISO 7042 / DIN 980
Deformed-top locking, high-temperature capable
M30
3.5
46.0
30.0
ISO 7042 / DIN 980
Deformed-top locking, high-temperature capable
M36
4.0
55.0
36.0
ISO 7042 / DIN 980
Deformed-top locking, high-temperature capable
Technical Drawing
Customize the parameters below — every spec field is editable, and the drawing redraws to match the values you choose. Changing the size will snap the other fields to that size's standard values; you can then override any individual value.
Sends the selected values to the quote form below.
Request a Quote
The form below follows the current technical drawing configuration. Change the drawing values above and the request details update automatically.
Dimensions & Specifications (ISO 7042 / DIN 980)
Size
Pitch (mm)
Width across flats s (mm)
Nut height m (mm)
Reference standard
Notes
M5
0.8
8.0
6.0
ISO 7042 / DIN 980
Deformed-top locking, high-temperature capable
M6
1.0
10.0
7.0
ISO 7042 / DIN 980
Deformed-top locking, high-temperature capable
M8
1.25
13.0
9.0
ISO 7042 / DIN 980
Deformed-top locking, high-temperature capable
M10
1.5
16.0
11.0
ISO 7042 / DIN 980
Deformed-top locking, high-temperature capable
M12
1.75
18.0
13.0
ISO 7042 / DIN 980
Deformed-top locking, high-temperature capable
M14
2.0
21.0
15.0
ISO 7042 / DIN 980
Deformed-top locking, high-temperature capable
M16
2.0
24.0
17.0
ISO 7042 / DIN 980
Deformed-top locking, high-temperature capable
M18
2.5
27.0
19.0
ISO 7042 / DIN 980
Deformed-top locking, high-temperature capable
M20
2.5
30.0
21.0
ISO 7042 / DIN 980
Deformed-top locking, high-temperature capable
M24
3.0
36.0
24.0
ISO 7042 / DIN 980
Deformed-top locking, high-temperature capable
M30
3.5
46.0
30.0
ISO 7042 / DIN 980
Deformed-top locking, high-temperature capable
M36
4.0
55.0
36.0
ISO 7042 / DIN 980
Deformed-top locking, high-temperature capable
Materials & Grades
Select a material class to see the grades we supply it in. Each designation is listed with its ISO/EN, AISI/SAE, JIS and GB equivalents.
Third-party video, selected automatically for this topic. It is not produced by Engineering Hardware and is not a specification source — use the tables on this page for dimensional data.
Inside the plant
Manufactured in our own plant
This part is cold-formed, threaded, heat-treated and finished in-house. The stages below are where its class and finish are actually decided.
01
Cold heading
Wire rod is drawn to size and cold-formed into blanks. Forming rather than cutting keeps the grain flow continuous around the head, which is where a bolt is most likely to fail.
Head dimensions and under-head radius checked at set-up and per shift.
02
Thread rolling
Threads are rolled between hardened dies rather than cut. Rolled threads are stronger in fatigue than cut threads and hold pitch and flank angle far more consistently across a batch.
Go / no-go ring gauges to ISO 965 tolerance class 6g.
03
Heat treatment
Quench-and-temper brings carbon and alloy steel to the property class ordered — 8.8, 10.9 or 12.9 — with the furnace charge tracked so a finished lot can be traced back to it.
Core hardness and tensile tested per lot to ISO 898-1.
04
Surface treatment
Zinc, zinc-nickel, hot-dip galvanizing, black oxide, phosphate and Dacromet, selected against the service environment rather than against the price list.
Coating thickness and neutral salt spray hours to ISO 9227.
Frequently Asked Questions
What corrosion resistance do Property Class 12.9 Steel All-Metal Lock Nuts offer?
Property Class 12.9 Steel All-Metal Lock Nuts provide requires plating or black-oxide protection with a service range of commonly limited to approx. +300 °C; confirm against the coating and the load.
When should I move from ISO 898-1 property class 12.9 to class 8.8 for All-Metal Lock Nuts?
Step up to class 8.8 when the joint preload approaches the proof load of the current class. The higher class adds preload at the same diameter, often saving size and weight.
Is Property Class 12.9 Steel prone to hydrogen embrittlement?
Class 10.9 and above can be susceptible to hydrogen embrittlement when electroplated. Specify post-plating baking, or use mechanical-zinc / zinc-flake finishes which avoid the cathodic plating step.
Which finish is best for outdoor All-Metal Lock Nuts?
For outdoor service in steel, hot-dip galvanizing gives the longest life; zinc-flake (Geomet/Delta-Tone family) gives a thinner film with excellent salt-spray performance; standard zinc plating is the lowest-cost option for general indoor / shielded outdoor use.
How do I request a quotation?
Use the technical drawing on this page to pick the exact configuration, then submit it with the quote form. We respond within one business day.
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