Specifying Internally Threaded Dowel Pin — GB/T 120.1 / ISO 8735 (Series 099) in Grade 8.8 Steel pairs the dimensional form of Internally Threaded Dowel Pin — GB/T 120.1 / ISO 8735 (Series 099) (GB/T 120.1 / ISO 8735) with the engineering properties of Grade 8.8 Steel. This page explains when to choose the grade, how it behaves in service, and which grades to compare it against.
Why Choose Grade 8.8 Steel for Internally Threaded Dowel Pin — GB/T 120.1 / ISO 8735 (Series 099)
The workhorse medium-carbon alloy grade for structural joints. For internally threaded dowel pin — gb/t 120.1 / iso 8735 (series 099), this matters when requires plating (zinc) for corrosion protection is the primary requirement.
Mechanical & Physical Properties
| Grade designation | class 8.8 |
|---|---|
| Magnetic response | Magnetic |
| Service temperature | up to approx. +300 °C |
| Corrosion characteristic | Requires plating (zinc) for corrosion protection |
Corrosion Behavior in Service
Carbon and alloy steel internally threaded dowel pin — gb/t 120.1 / iso 8735 (series 099) 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 Internally Threaded Dowel Pin — GB/T 120.1 / ISO 8735 (Series 099), class 10.9 or 12.9 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 Internally Threaded Dowel Pin — GB/T 120.1 / ISO 8735 (Series 099) Available in Grade 8.8 Steel
| Nominal diameter d (mm) | Length L (mm) | Internal thread | Material | Reference standard |
|---|---|---|---|---|
| 4 | 16 | M3 | Alloy steel | ISO 8736 / GB/T 120 |
| 5 | 20 | M4 | Alloy steel | ISO 8736 / GB/T 120 |
| 6 | 24 | M4 | Alloy steel | ISO 8736 / GB/T 120 |
| 8 | 30 | M5 | Alloy steel | ISO 8736 / GB/T 120 |
| 10 | 40 | M6 | Alloy steel | ISO 8736 / GB/T 120 |
| 12 | 50 | M8 | Alloy steel | ISO 8736 / GB/T 120 |
| 16 | 60 | M10 | Alloy steel | ISO 8736 / GB/T 120 |
| 20 | 80 | M12 | Alloy steel | ISO 8736 / GB/T 120 |
