Property Class 12.9 Steel Closed-End Round-Body Blind Rivet Nuts
Mechanical properties, corrosion behaviour and the full dimensional range for this grade.
Property Class 12.9 Steel Closed-End Round-Body Blind Rivet 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.
Closed-End Round-Body Blind Rivet Nuts manufactured in Property Class 12.9 Steel (ISO 898-1 property class 12.9) are dimensioned to Trade series (closed-end blind rivet nuts). The sections below give the mechanical and physical properties of the grade, its behavior in corrosive and elevated-temperature service, and the full size table.
Why Choose Property Class 12.9 Steel for Closed-End Round-Body Blind Rivet Nuts
The highest common strength class, for high-load machine assembly. For closed-end round-body blind rivet 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 closed-end round-body blind rivet 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.
Comparable Grades
For Closed-End Round-Body Blind Rivet Nuts, 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 Closed-End Round-Body Blind Rivet Nuts Available in Property Class 12.9 Steel
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 (closed-end blind rivet nuts))
What Closed-End Round-Body Blind Rivet Nuts are specified for, industry by industry. Stocked from M4 to M10.
Industries that specify Closed-End Round-Body Blind Rivet Nuts
Outdoor enclosuresCover and bracket attachment points exposed to water and dirt.
HVAC fabricationPanel hardware installed after the duct or enclosure has been formed.
Refrigeration equipmentSealed threaded mounting points in formed panels and closed housings.
Vehicle bodyworkBlind threads in rails and box sections where the cavity must stay closed.
Automotive & transportVibration-prone joints where the locking type is specified on the drawing.
Maintenance & MROReplacements matched to the existing bolt class, thread and finish.
Typical applications
forming the blind bulb within the specified grip range
choosing steel, stainless steel or aluminum for the service environment
adding a sealed internal thread from the front face of a panel
keeping water and debris out of a closed section behind the insert
joints re-torqued at a service interval
completing a bolted joint on a stud, rod or bolt
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.
Where to use something else
Do not drill to the thread minor diameter; the installation hole is set by the body and forming requirements.
Video: Property Class 12.9 Steel Closed-End Round-Body Blind Rivet Nuts
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
Which finish is best for outdoor Closed-End Round-Body Blind Rivet 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 12.9 Steel?
The practical service range is commonly limited to approx. +300 °C; confirm against the coating and the load.
Can Property Class 12.9 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.
Are Property Class 12.9 Steel Closed-End Round-Body Blind Rivet Nuts magnetic?
Property Class 12.9 Steel Closed-End Round-Body Blind Rivet Nuts are magnetic.
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.
Need a fastener quote or a spec sheet?Message our engineers on WhatsApp — send a drawing or DIN number and get pricing back fast.Start WhatsApp Chat →
This website uses only necessary and functional cookies to operate, secure, and improve basic website performance.
We do not use advertising cookies, Google Analytics, or cross-site tracking technologies.
Privacy Policy
