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 hexalobular socket cheese head screws are specified in this grade, the dimensions remain per ISO 14580; 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 Hexalobular Socket Cheese Head Screws
The most common stainless group for indoor and general outdoor fasteners. For hexalobular socket cheese head screws, 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
Two important notes for stainless hexalobular socket cheese head screws: (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.
Comparable Grades
For Hexalobular Socket Cheese Head Screws, 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
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 Hexalobular Socket Cheese Head Screws Available in A2 Stainless Steel
| Size | Pitch P (mm) | a (mm) | b (mm) | Head diameter dk (mm) | dk_mean (mm) | da (mm) | Head height k (mm) | n_min (mm) | r (mm) | t_min (mm) | x (mm) | Length range l (mm) | Reference standard |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| M1.6 | 0.35 | 0.7 | 25.0 | 3.0 | 2.9 | 2.0 | 1.1 | 0.46 | 0.1 | 0.45 | 0.9 | 2~16 | ISO 14580 |
| M2 | 0.4 | 0.8 | 25.0 | 3.8 | 3.7 | 2.6 | 1.4 | 0.56 | 0.1 | 0.6 | 1.0 | 3~20 | ISO 14580 |
| M2.5 | 0.45 | 0.9 | 25.0 | 4.5 | 4.4 | 3.1 | 1.8 | 0.66 | 0.1 | 0.7 | 1.1 | 3~25 | ISO 14580 |
| M3 | 0.5 | 1.0 | 25.0 | 5.5 | 5.4 | 3.6 | 2.0 | 0.86 | 0.1 | 0.85 | 1.25 | 4~30 | ISO 14580 |
| (M3.5) | 0.6 | 1.2 | 38.0 | 6.0 | 5.9 | 4.1 | 2.4 | 1.06 | 0.1 | 1.0 | 1.5 | 5~35 | ISO 14580 |
| M4 | 0.7 | 1.4 | 38.0 | 7.0 | 6.9 | 4.7 | 2.6 | 1.26 | 0.2 | 1.1 | 1.75 | 5~40 | ISO 14580 |
| M5 | 0.8 | 1.6 | 38.0 | 8.5 | 8.4 | 5.7 | 3.3 | 1.26 | 0.2 | 1.3 | 2.0 | 6~50 | ISO 14580 |
| M6 | 1.0 | 2.0 | 38.0 | 10.0 | 9.9 | 6.8 | 3.9 | 1.66 | 0.25 | 1.6 | 2.5 | 8~60 | ISO 14580 |
| M8 | 1.25 | 2.5 | 38.0 | 13.0 | 12.85 | 9.2 | 5.0 | 2.06 | 0.4 | 2.0 | 3.2 | 10~80 | ISO 14580 |
| M10 | 1.5 | 3.0 | 38.0 | 16.0 | 15.85 | 11.2 | 6.0 | 2.56 | 0.4 | 2.4 | 3.8 | 12~80 | ISO 14580 |
Dimensions are independent of the material: every size above is available in A2 Stainless Steel.
Custom manufacturing · Made to drawing
Need this screw in a grade that is not listed?
A2 Stainless Steel is one of the grades the catalog describes. Where the standard stops, the drawing takes over: fine pitches, left-hand threads, partial threading, and property classes above the catalogued grade where material and heat treatment allow. Made by cold heading or warm forging.
Minimum order from 2,000 pieces; samples within 7 days of drawing approval.
