Taper Keys (DIN 6886) manufactured in A4 Stainless Steel (ISO 3506 group A4 (316 / 1.4401), commonly supplied A4-80) are dimensioned to DIN 6886 (taper keys) — 1:100 taper. 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 A4 Stainless Steel for Taper Keys (DIN 6886)
Specified for marine, coastal and chemical applications. For taper keys (din 6886), this matters when superior, including marine and chloride environments is the primary requirement.
Mechanical & Physical Properties
| Grade designation | ISO 3506 group A4 (316 / 1.4401), commonly supplied A4-80 |
|---|---|
| Magnetic response | Largely non-magnetic |
| Service temperature | approx. -200 °C to +400 °C, subject to the property class and the joint |
| Corrosion characteristic | Superior, including marine and chloride environments |
Corrosion Behavior in Service
A4 (316) adds 2–3% molybdenum to the A2 (304) composition, which dramatically improves resistance to chloride-pitting corrosion. For Taper Keys (DIN 6886) in marine, coastal, swimming-pool or food-processing environments, A4 is the default selection.
Comparable Grades
For Taper Keys (DIN 6886), the alternative stainless grade is A2 (304). 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
The galvanic couple here runs the wrong way: aluminum is the less noble metal, so it corrodes and the fastener does not. What governs the rate is the ratio of areas — a large anode and a small cathode is a tolerable combination, the reverse concentrates the attack into thin material around the hole. An isolating washer plus sealant breaks the circuit; where that is impractical, match the fastener to the substrate.
Sizes of Taper Keys (DIN 6886) Available in A4 Stainless Steel
| Shaft diameter over | to and including | Key width b (mm) | Key height h (mm) | Taper |
|---|---|---|---|---|
| 10 | 12 | 4 | 4 | 1:100 |
| 12 | 17 | 5 | 5 | 1:100 |
| 17 | 22 | 6 | 6 | 1:100 |
| 22 | 30 | 8 | 7 | 1:100 |
| 30 | 38 | 10 | 8 | 1:100 |
| 38 | 44 | 12 | 8 | 1:100 |
| 44 | 50 | 14 | 9 | 1:100 |
| 50 | 58 | 16 | 10 | 1:100 |
| 58 | 65 | 18 | 11 | 1:100 |
| 65 | 75 | 20 | 12 | 1:100 |
| 75 | 85 | 22 | 14 | 1:100 |
| 85 | 95 | 25 | 14 | 1:100 |
