Material page for drilled-spanner security screws in A2 Stainless Steel (ISO 3506 group A2 (304 / 1.4301), commonly supplied A2-70). The sizes below are the ones we supply; there is no published dimensional standard for this article, so the table rather than a standard number is what to quote. Corrosion behaviour is good general corrosion resistance and the service range is approx. -200 °C to +400 °C, subject to the property class and the joint.
Why Choose A2 Stainless Steel for Drilled-Spanner Security Screws
The most common stainless group for indoor and general outdoor fasteners. For drilled-spanner security 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 |
Corrosion Behavior in Service
A2 (304) gives excellent atmospheric and most-water corrosion resistance and is the most common stainless for Drilled-Spanner Security Screws in indoor and general outdoor service. In chloride-bearing environments (marine air, road salt, swimming pools) consider stepping up to A4 (316).
Comparable Grades
For Drilled-Spanner Security 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
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 Drilled-Spanner Security Screws Available in A2 Stainless Steel
| Thread size | Head form | Head diameter (in) | Head height (in) | Length options (in) | Drive | Material |
|---|---|---|---|---|---|---|
| 4-40 undercut | flat 82-degree | 0.225 | 0.047 | 1/4 | two-hole drilled spanner | 18-8 stainless steel |
| 6-32 standard | flat 82-degree | 0.262 | 0.083 | 1/4~2 | two-hole drilled spanner | 18-8 stainless steel |
| 8-32 standard | flat 82-degree | 0.312 | 0.100 | 1/4~2 | two-hole drilled spanner | 18-8 stainless steel |
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. Lengths and thread lengths outside the standard table are the commonest request, followed by a drive the standard does not offer and a head marked with your own part number. Made by cold heading or warm forging.
Minimum order from 2,000 pieces; samples within 7 days of drawing approval.
