A2 Stainless Steel (ISO 3506 group A2 (304 / 1.4301), commonly supplied A2-70) is the most common stainless group for indoor and general outdoor fasteners. When grooved pins, taper and center-groove types are specified in this grade, the dimensions remain per ISO 8741 / ISO 8742 / ISO 8743 / ISO 8744 / ISO 8745; the material determines corrosion behavior (good general corrosion resistance) and the service temperature range (approx. -200 °C to +400 °C, subject to the property class and the joint). Both are covered below with the size table.
Why Choose A2 Stainless Steel for Grooved Pins, Taper and Center-Groove Types
The most common stainless group for indoor and general outdoor fasteners. For grooved pins, taper and center-groove types, this matters when good general corrosion resistance is the primary requirement.
Mechanical & Physical Properties
| Grade designation | ISO 3506 group A2 (304 / 1.4301), commonly supplied A2-70 |
|---|---|
| Magnetic response | Largely non-magnetic |
| Service temperature | approx. -200 °C to +400 °C, subject to the property class and the joint |
| Corrosion characteristic | Good general corrosion resistance |
Galvanic & Galling Considerations
For stainless grooved pins, taper and center-groove types the compatibility question is galvanic rather than galling: joined to aluminum or galvanized steel in wet service, stainless drives corrosion of the less-noble metal. Isolate with a coating, sleeve or non-conductive washer where the joint sees moisture. Note also that stainless is softer than hardened carbon steel, so where the part carries a wear or shear duty, check the load against the grade before substituting.
Comparable Grades
For Grooved Pins, Taper and Center-Groove Types, the alternative stainless grade is A4 (316). Choose A2 (304) for general use and A4 (316) wherever chlorides are present; the molybdenum in A4 is the whole difference. Remember that stainless is the corrosion answer, not the strength answer — for load, look at class 8.8 or 10.9 instead.
Using Stainless Fasteners in Aluminum
Expect the aluminum to corrode, not the fastener — stainless sits higher in the galvanic series, so the aluminum is the one that gives up material. A small fastener in a thick section spreads the loss over a large area and is usually fine; a large fastener in thin sheet concentrates it and is not. Keep water out of the joint, or isolate the two metals with a nylon or coated washer and a sealant.
Sizes of Grooved Pins, Taper and Center-Groove Types Available in A2 Stainless Steel
| Nominal diameter d (mm) | Type | d_1 (mm) | a (mm) | d1 (mm) | Length range l (mm) | Reference standard |
|---|---|---|---|---|---|---|
| 1.5 mm | Half-length reverse taper grooved pins | 1.5 | 0.2 | 8~20 | ISO 8741 / ISO 8742 / ISO 8743 / ISO 8744 / ISO 8745 | |
| 2 mm | Half-length reverse taper grooved pins | 2 | 0.25 | 8~30 | ISO 8741 / ISO 8742 / ISO 8743 / ISO 8744 / ISO 8745 | |
| 2.5 mm | Half-length reverse taper grooved pins | 2.5 | 0.3 | 8~30 | ISO 8741 / ISO 8742 / ISO 8743 / ISO 8744 / ISO 8745 | |
| 3 mm | Half-length reverse taper grooved pins | 3 | 0.4 | 8~40 | ISO 8741 / ISO 8742 / ISO 8743 / ISO 8744 / ISO 8745 | |
| 4 mm | Half-length reverse taper grooved pins | 4 | 0.5 | 10~60 | ISO 8741 / ISO 8742 / ISO 8743 / ISO 8744 / ISO 8745 | |
| 5 mm | Half-length reverse taper grooved pins | 5 | 0.63 | 10~60 | ISO 8741 / ISO 8742 / ISO 8743 / ISO 8744 / ISO 8745 | |
| 6 mm | Half-length reverse taper grooved pins | 6 | 0.8 | 12~80 | ISO 8741 / ISO 8742 / ISO 8743 / ISO 8744 / ISO 8745 | |
| 8 mm | Half-length reverse taper grooved pins | 8 | 1 | 14~100 | ISO 8741 / ISO 8742 / ISO 8743 / ISO 8744 / ISO 8745 | |
| 10 mm | Half-length reverse taper grooved pins | 10 | 1.2 | 18~160 | ISO 8741 / ISO 8742 / ISO 8743 / ISO 8744 / ISO 8745 | |
| 12 mm | Half-length reverse taper grooved pins | 12 | 1.6 | 26~200 | ISO 8741 / ISO 8742 / ISO 8743 / ISO 8744 / ISO 8745 | |
| 16 mm | Half-length reverse taper grooved pins | 16 | 2 | 26~200 | ISO 8741 / ISO 8742 / ISO 8743 / ISO 8744 / ISO 8745 | |
| 20 mm | Half-length reverse taper grooved pins | 20 | 2.5 | 26~200 | ISO 8741 / ISO 8742 / ISO 8743 / ISO 8744 / ISO 8745 | |
| 25 mm | Half-length reverse taper grooved pins | 25 | 3 | 26~200 | ISO 8741 / ISO 8742 / ISO 8743 / ISO 8744 / ISO 8745 | |
| 1.5 mm | Third-length center grooved pins | 1.5 | 0.2 | 8~20 | ISO 8741 / ISO 8742 / ISO 8743 / ISO 8744 / ISO 8745 | |
| 1.5 mm | Half-length center grooved pins | 1.5 | 0.2 | 8~20 | ISO 8741 / ISO 8742 / ISO 8743 / ISO 8744 / ISO 8745 | |
| 2 mm | Third-length center grooved pins | 2 | 0.25 | 12~30 | ISO 8741 / ISO 8742 / ISO 8743 / ISO 8744 / ISO 8745 | |
| 2 mm | Half-length center grooved pins | 2 | 0.25 | 12~30 | ISO 8741 / ISO 8742 / ISO 8743 / ISO 8744 / ISO 8745 | |
| 2.5 mm | Third-length center grooved pins | 2.5 | 0.3 | 12~30 | ISO 8741 / ISO 8742 / ISO 8743 / ISO 8744 / ISO 8745 | |
| 2.5 mm | Half-length center grooved pins | 2.5 | 0.3 | 12~30 | ISO 8741 / ISO 8742 / ISO 8743 / ISO 8744 / ISO 8745 | |
| 3 mm | Third-length center grooved pins | 3 | 0.4 | 12~40 | ISO 8741 / ISO 8742 / ISO 8743 / ISO 8744 / ISO 8745 | |
| 3 mm | Half-length center grooved pins | 3 | 0.4 | 12~40 | ISO 8741 / ISO 8742 / ISO 8743 / ISO 8744 / ISO 8745 | |
| 4 mm | Third-length center grooved pins | 4 | 0.5 | 18~60 | ISO 8741 / ISO 8742 / ISO 8743 / ISO 8744 / ISO 8745 | |
| 4 mm | Half-length center grooved pins | 4 | 0.5 | 18~60 | ISO 8741 / ISO 8742 / ISO 8743 / ISO 8744 / ISO 8745 | |
| 5 mm | Third-length center grooved pins | 5 | 0.63 | 18~60 | ISO 8741 / ISO 8742 / ISO 8743 / ISO 8744 / ISO 8745 | |
| 5 mm | Half-length center grooved pins | 5 | 0.63 | 18~60 | ISO 8741 / ISO 8742 / ISO 8743 / ISO 8744 / ISO 8745 | |
| 6 mm | Third-length center grooved pins | 6 | 0.8 | 22~80 | ISO 8741 / ISO 8742 / ISO 8743 / ISO 8744 / ISO 8745 | |
| 6 mm | Half-length center grooved pins | 6 | 0.8 | 22~80 | ISO 8741 / ISO 8742 / ISO 8743 / ISO 8744 / ISO 8745 | |
| 8 mm | Third-length center grooved pins | 8 | 1 | 26~100 | ISO 8741 / ISO 8742 / ISO 8743 / ISO 8744 / ISO 8745 | |
| 8 mm | Half-length center grooved pins | 8 | 1 | 26~100 | ISO 8741 / ISO 8742 / ISO 8743 / ISO 8744 / ISO 8745 | |
| 10 mm | Third-length center grooved pins | 10 | 1.2 | 32~160 | ISO 8741 / ISO 8742 / ISO 8743 / ISO 8744 / ISO 8745 |
Dimensions are independent of the material: every size above is available in A2 Stainless Steel.
Custom manufacturing · Made to drawing
Need this pin in a grade that is not listed?
A2 Stainless Steel is one of the grades the catalog describes. Tolerance class is what a special pin usually turns on — a locating pin and a retaining pin want very different fits in the same nominal size. Made by cold heading or turning.
Minimum order from 2,000 pieces; samples within 7 days of drawing approval.

