Specifying Taper Pins in Grade 8.8 Steel pairs the dimensional form of Taper Pins (ISO 2339 / DIN 1) 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 Taper Pins
The workhorse medium-carbon alloy grade for structural joints. For taper pins, 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 taper pins 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 taper pins 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 Taper Pins Available in Grade 8.8 Steel
| Small-end diameter (mm) | Taper | Common length range (mm) | Material | Reference standard | Notes |
|---|---|---|---|---|---|
| 0.6 | 1:50 | 4~16 | Carbon steel / stainless | ISO 2339 / DIN 1 (type A) | Large end = small end + length/50 |
| 0.8 | 1:50 | 5~20 | Carbon steel / stainless | ISO 2339 / DIN 1 (type A) | Large end = small end + length/50 |
| 1.0 | 1:50 | 6~25 | Carbon steel / stainless | ISO 2339 / DIN 1 (type A) | Large end = small end + length/50 |
| 1.2 | 1:50 | 6~25 | Carbon steel / stainless | ISO 2339 / DIN 1 (type A) | Large end = small end + length/50 |
| 1.5 | 1:50 | 8~32 | Carbon steel / stainless | ISO 2339 / DIN 1 (type A) | Large end = small end + length/50 |
| 2.0 | 1:50 | 10~45 | Carbon steel / stainless | ISO 2339 / DIN 1 (type A) | Large end = small end + length/50 |
| 2.5 | 1:50 | 12~50 | Carbon steel / stainless | ISO 2339 / DIN 1 (type A) | Large end = small end + length/50 |
| 3.0 | 1:50 | 14~55 | Carbon steel / stainless | ISO 2339 / DIN 1 (type A) | Large end = small end + length/50 |
| 4.0 | 1:50 | 16~70 | Carbon steel / stainless | ISO 2339 / DIN 1 (type A) | Large end = small end + length/50 |
| 5.0 | 1:50 | 18~90 | Carbon steel / stainless | ISO 2339 / DIN 1 (type A) | Large end = small end + length/50 |
| 6.0 | 1:50 | 22~110 | Carbon steel / stainless | ISO 2339 / DIN 1 (type A) | Large end = small end + length/50 |
| 8.0 | 1:50 | 28~140 | Carbon steel / stainless | ISO 2339 / DIN 1 (type A) | Large end = small end + length/50 |
| 10.0 | 1:50 | 35~180 | Carbon steel / stainless | ISO 2339 / DIN 1 (type A) | Large end = small end + length/50 |
| 12.0 | 1:50 | 45~200 | Carbon steel / stainless | ISO 2339 / DIN 1 (type A) | Large end = small end + length/50 |
| 16.0 | 1:50 | 55~200 | Carbon steel / stainless | ISO 2339 / DIN 1 (type A) | Large end = small end + length/50 |
| 20.0 | 1:50 | 65~200 | Carbon steel / stainless | ISO 2339 / DIN 1 (type A) | Large end = small end + length/50 |
| 25.0 | 1:50 | 80~200 | Carbon steel / stainless | ISO 2339 / DIN 1 (type A) | Large end = small end + length/50 |
| 30.0 | 1:50 | 100~200 | Carbon steel / stainless | ISO 2339 / DIN 1 (type A) | Large end = small end + length/50 |
| 40.0 | 1:50 | 120~200 | Carbon steel / stainless | ISO 2339 / DIN 1 (type A) | Large end = small end + length/50 |
| 50.0 | 1:50 | 160~200 | Carbon steel / stainless | ISO 2339 / DIN 1 (type A) | Large end = small end + length/50 |