Mechanical properties, corrosion behaviour and the full dimensional range for this grade.
Property Class 8.8 Steel Hex Nut 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 Hex Nut are supplied to GB/T 6170 / ISO 4032. 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 Hex Nut — GB/T 6170 / ISO 4032 (Series 059)
The workhorse medium-carbon alloy class for structural joints. For hex nut — gb/t 6170 / iso 4032 (series 059), 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 hex nut — gb/t 6170 / iso 4032 (series 059) 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 hex nut — gb/t 6170 / iso 4032 (series 059) 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 Hex Nut — GB/T 6170 / ISO 4032 (Series 059) Available in Property Class 8.8 Steel
Size
Pitch (mm)
Width across flats s (mm)
Width across corners e (mm)
Nut height m (mm)
Reference standard
M3
0.5
5.5
6.01
2.4
ISO 4032 / GB/T 6170
M4
0.7
7.0
7.66
3.2
ISO 4032 / GB/T 6170
M5
0.8
8.0
8.79
4.7
ISO 4032 / GB/T 6170
M6
1.0
10.0
11.05
5.2
ISO 4032 / GB/T 6170
M8
1.25
13.0
14.38
6.8
ISO 4032 / GB/T 6170
M10
1.5
16.0
17.77
8.4
ISO 4032 / GB/T 6170
M12
1.75
18.0
20.03
10.8
ISO 4032 / GB/T 6170
M14
2.0
21.0
23.36
12.8
ISO 4032 / GB/T 6170
M16
2.0
24.0
26.75
14.8
ISO 4032 / GB/T 6170
M18
2.5
27.0
30.14
15.8
ISO 4032 / GB/T 6170
M20
2.5
30.0
33.53
18.0
ISO 4032 / GB/T 6170
M24
3.0
36.0
39.98
21.5
ISO 4032 / GB/T 6170
M30
3.5
46.0
50.85
25.6
ISO 4032 / GB/T 6170
M36
4.0
55.0
60.79
31.0
ISO 4032 / GB/T 6170
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 (GB/T 6170 / ISO 4032)
Size
Pitch (mm)
Width across flats s (mm)
Width across corners e (mm)
Nut height m (mm)
Reference standard
M3
0.5
5.5
6.01
2.4
ISO 4032 / GB/T 6170
M4
0.7
7.0
7.66
3.2
ISO 4032 / GB/T 6170
M5
0.8
8.0
8.79
4.7
ISO 4032 / GB/T 6170
M6
1.0
10.0
11.05
5.2
ISO 4032 / GB/T 6170
M8
1.25
13.0
14.38
6.8
ISO 4032 / GB/T 6170
M10
1.5
16.0
17.77
8.4
ISO 4032 / GB/T 6170
M12
1.75
18.0
20.03
10.8
ISO 4032 / GB/T 6170
M14
2.0
21.0
23.36
12.8
ISO 4032 / GB/T 6170
M16
2.0
24.0
26.75
14.8
ISO 4032 / GB/T 6170
M18
2.5
27.0
30.14
15.8
ISO 4032 / GB/T 6170
M20
2.5
30.0
33.53
18.0
ISO 4032 / GB/T 6170
M24
3.0
36.0
39.98
21.5
ISO 4032 / GB/T 6170
M30
3.5
46.0
50.85
25.6
ISO 4032 / GB/T 6170
M36
4.0
55.0
60.79
31.0
ISO 4032 / GB/T 6170
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
Which finish is best for outdoor Hex Nut — GB/T 6170 / ISO 4032 (Series 059)?
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.
Are Property Class 8.8 Steel Hex Nut — GB/T 6170 / ISO 4032 (Series 059) magnetic?
Property Class 8.8 Steel Hex Nut — GB/T 6170 / ISO 4032 (Series 059) 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.
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