Property Class 12.9 Steel Cross Dowel Furniture Nuts
Mechanical properties, corrosion behaviour and the full dimensional range for this grade.
Property Class 12.9 Steel Cross Dowel Furniture 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
For cross dowel furniture nuts in Property Class 12.9 Steel, the controlling selection factors are corrosion exposure, strength requirement and service temperature. The grade data for Property Class 12.9 Steel (ISO 898-1 property class 12.9) is summarized below together with every size supplied.
Why Choose Property Class 12.9 Steel for Cross Dowel Furniture Nuts
The highest common strength class, for high-load machine assembly. For cross dowel furniture 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 cross dowel furniture 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 cross dowel furniture 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 Cross Dowel Furniture Nuts Available in Property Class 12.9 Steel
Thread size
Diameter options (mm)
Length options (mm)
Body form
Material options
M4
6
15
cross-drilled perpendicular barrel
galvanized steel / 1.4305 stainless steel
M5
8
18
cross-drilled perpendicular barrel
galvanized steel / 1.4305 stainless steel
M6
8 or 9
19
cross-drilled perpendicular barrel
galvanized steel / 1.4305 stainless steel
M8
10~12
22~60
cross-drilled perpendicular barrel
galvanized steel / 1.4305 stainless steel
M10
12~16
20~50
cross-drilled perpendicular barrel
galvanized steel / 1.4305 stainless steel
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 (Trade series (cross dowel nuts))
Thread size
Diameter options (mm)
Length options (mm)
Body form
Material options
M4
6
15
cross-drilled perpendicular barrel
galvanized steel / 1.4305 stainless steel
M5
8
18
cross-drilled perpendicular barrel
galvanized steel / 1.4305 stainless steel
M6
8 or 9
19
cross-drilled perpendicular barrel
galvanized steel / 1.4305 stainless steel
M8
10~12
22~60
cross-drilled perpendicular barrel
galvanized steel / 1.4305 stainless steel
M10
12~16
20~50
cross-drilled perpendicular barrel
galvanized steel / 1.4305 stainless steel
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.
Flat-pack furnitureCross dowel nuts clamp panels where the bolt enters perpendicular to the barrel.
Cabinet productionGalvanized and stainless barrels provide a hidden threaded joint.
Machine building & OEMThe clamping counter-face on studs and bolts throughout an assembly.
Steel fabricationBolted structural and frame connections.
Typical applications
selecting a length that fits the blind bore
using galvanized steel or 1.4305 stainless
aligning a cross-drilled barrel with a mating bolt
choosing M4 through M10 and the barrel diameter
locking an adjustment so it cannot drift
joints re-torqued at a service interval
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.
Exterior structural
Hot-dip galvanised options for external steelwork; allow for the thicker coating in the mating thread.
Match the class
A nut below the bolt property class strips before the bolt reaches its own limit — pair class 8 nuts with 8.8 bolts, class 10 with 10.9.
Where to use something else
Do not drill the cross bore from the visible face without a positioning jig; misalignment prevents the bolt from entering.
Need help matching Cross Dowel Furniture Nuts to your application? Send the assembly, the load and the environment with your enquiry and we will specify the size, material and finish against them.
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
Are Property Class 12.9 Steel Cross Dowel Furniture Nuts magnetic?
Property Class 12.9 Steel Cross Dowel Furniture Nuts are magnetic.
What corrosion resistance do Property Class 12.9 Steel Cross Dowel Furniture Nuts offer?
Property Class 12.9 Steel Cross Dowel Furniture 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 Cross Dowel Furniture 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.
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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