Nuts · Trade series (self-clinching, IFI-111 practice)
Property Class 8.8 Steel Self-Clinching Press-Fit Nuts
Mechanical properties, corrosion behaviour and the full dimensional range for this grade.
Property Class 8.8 Steel Self-Clinching Press-Fit Nuts are supplied to ISO 898-1 property class 8.8. Corrosion behaviour is requires plating (zinc) for corrosion 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 workhorse medium-carbon alloy class for structural joints.
Grade
ISO 898-1 property class 8.8
Corrosion resistance
Requires plating (zinc) for corrosion 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 8.8 Steel Self-Clinching Press-Fit Nuts are supplied to Trade series (self-clinching, IFI-111 practice). The grade provides requires plating (zinc) for corrosion 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 8.8 Steel for Self-Clinching Press-Fit Nuts
The workhorse medium-carbon alloy class for structural joints. For self-clinching press-fit nuts, this matters when requires plating (zinc) for corrosion protection is the primary requirement.
Mechanical & Physical Properties
Grade designation
ISO 898-1 property class 8.8
Magnetic response
Magnetic
Service temperature
commonly limited to approx. +300 °C; confirm against the coating and the load
Corrosion characteristic
Requires plating (zinc) for corrosion protection
Corrosion Behavior in Service
Carbon and alloy steel self-clinching press-fit 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 self-clinching press-fit 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 Self-Clinching Press-Fit Nuts Available in Property Class 8.8 Steel
Thread size
Shank diameter (mm)
Length (mm)
Hole in sheet (mm)
Minimum sheet thickness (mm)
Maximum sheet hardness
Material
Installation
M3
4.20
3.30
4.22
0.8
HRB 80
Case-hardened steel
Press, squeeze
M4
5.40
3.80
5.42
0.8
HRB 80
Case-hardened steel
Press, squeeze
M5
6.35
4.20
6.38
1.0
HRB 80
Case-hardened steel
Press, squeeze
M6
7.95
4.80
7.98
1.0
HRB 80
Case-hardened steel
Press, squeeze
M8
9.55
5.70
9.58
1.5
HRB 80
Case-hardened steel
Press, squeeze
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 (self-clinching, IFI-111 practice))
Thread size
Shank diameter (mm)
Length (mm)
Hole in sheet (mm)
Minimum sheet thickness (mm)
Maximum sheet hardness
Material
Installation
M3
4.20
3.30
4.22
0.8
HRB 80
Case-hardened steel
Press, squeeze
M4
5.40
3.80
5.42
0.8
HRB 80
Case-hardened steel
Press, squeeze
M5
6.35
4.20
6.38
1.0
HRB 80
Case-hardened steel
Press, squeeze
M6
7.95
4.80
7.98
1.0
HRB 80
Case-hardened steel
Press, squeeze
M8
9.55
5.70
9.58
1.5
HRB 80
Case-hardened steel
Press, squeeze
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.
Sheet metal fabricationThreads in enclosure and chassis panels on the press line.
Electronics enclosuresCaptive threads for lids, brackets and PCB mounts.
Automotive & transportVibration-prone joints where the locking type is specified on the drawing.
Maintenance & MROReplacements matched to the existing bolt class, thread and finish.
Building servicesThreaded rod, channel and suspension assemblies.
Typical applications
limited by sheet HARDNESS, not sheet thickness
a permanent torque-resistant thread in sheet too thin to tap
installed by press, never by hammer
joints re-torqued at a service interval
completing a bolted joint on a stud, rod or bolt
locking an adjustment so it cannot drift
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.
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.
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
Is Property Class 8.8 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 Self-Clinching Press-Fit 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.
What's the service temperature limit for Property Class 8.8 Steel?
The practical service range is commonly limited to approx. +300 °C; confirm against the coating and the load.
Can Property Class 8.8 Steel replace stainless steel structurally?
No — stainless A2/A4 cannot match class 10.9 / 12.9 strength. Stainless is selected for corrosion, not raw strength.
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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