For dowel screws (wood-to-metal) in A2 Stainless Steel, the controlling selection factors are corrosion exposure, strength requirement and service temperature. The grade data for A2 Stainless Steel (ISO 3506 group A2 (304 / 1.4301), commonly supplied A2-70) is summarized below together with every size supplied.
Why Choose A2 Stainless Steel for Dowel Screws (Wood-to-Metal)
The most common stainless group for indoor and general outdoor fasteners. For dowel screws (wood-to-metal), 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 |
Corrosion Behavior in Service
A2 (304) gives excellent atmospheric and most-water corrosion resistance and is the most common stainless for Dowel Screws (Wood-to-Metal) in indoor and general outdoor service. In chloride-bearing environments (marine air, road salt, swimming pools) consider stepping up to A4 (316).
Galvanic & Galling Considerations
Two important notes for stainless dowel screws (wood-to-metal): (1) stainless can gall on stainless threads under load — use a thread lubricant or anti-galling compound, especially for M6 and below; (2) when joined to aluminum or galvanized steel, stainless can drive galvanic corrosion of the less-noble metal in wet service — isolate with a coating or sleeve where appropriate.
Using Stainless Fasteners in Aluminum
Stainless steel is more noble than aluminum, so with an electrolyte present — rain, condensation, salt spray — the aluminum becomes the anode and corrodes at the joint. Area ratio decides how bad it gets: a small stainless fastener in a large aluminum section is normally acceptable, a large stainless fastener in thin aluminum is not. Where the joint gets wet, isolate the metals with a coated or nylon washer and a sealant, or specify an aluminum or coated fastener instead.
Sizes of Dowel Screws (Wood-to-Metal) Available in A2 Stainless Steel
| Machine thread | Wood end nominal (mm) | Overall length (mm) | Wood end length (mm) | Machine end length (mm) | Pilot hole in hardwood (mm) | Material |
|---|---|---|---|---|---|---|
| M5 | 5.0 | 40 | 20 | 16 | 3.2 | Steel zinc plated |
| M6 | 6.0 | 50 | 25 | 20 | 4.0 | Steel zinc plated |
| M6 | 6.0 | 60 | 30 | 25 | 4.0 | Steel zinc plated |
| M8 | 8.0 | 70 | 35 | 30 | 5.5 | Steel zinc plated |
| M8 | 8.0 | 80 | 40 | 35 | 5.5 | Steel zinc plated |
| M10 | 10.0 | 100 | 50 | 45 | 7.0 | Steel zinc plated |
