Material specification page for thread cutting screws (type f) in A4 Stainless Steel. Covers the grade designation (ISO 3506 group A4 (316 / 1.4401), commonly supplied A4-80), corrosion and magnetic behavior, comparable grades and their trade-offs, and the sizes available to DIN 7516.
Why Choose A4 Stainless Steel for Thread Cutting Screws (Type F)
Specified for marine, coastal and chemical applications. For thread cutting screws (type f), 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 Thread Cutting Screws (Type F) in marine, coastal, swimming-pool or food-processing environments, A4 is the default selection.
Comparable Grades
For Thread Cutting Screws (Type F), the alternative stainless grade is A2 (304). A2 (304) covers general indoor and outdoor service. A4 (316) adds molybdenum, which is what buys the chloride resistance for marine and de-icing-salt exposure. Where strength matters more than corrosion, plated alloy steel in class 8.8 or 10.9 is the swap to make.
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 Thread Cutting Screws (Type F) Available in A4 Stainless Steel
| Thread size | Pitch (mm) | Head diameter dk (mm) | Head height k (mm) | Core hole in steel (mm) | Common length range (mm) | Reference standard |
|---|---|---|---|---|---|---|
| M3 | 0.5 | 5.6 | 2.4 | 2.65 | 6~25 | DIN 7516 |
| M4 | 0.7 | 8.0 | 3.1 | 3.55 | 8~30 | DIN 7516 |
| M5 | 0.8 | 9.5 | 3.7 | 4.50 | 8~40 | DIN 7516 |
| M6 | 1.0 | 12.0 | 4.6 | 5.40 | 10~50 | DIN 7516 |
| M8 | 1.25 | 16.0 | 6.0 | 7.20 | 12~50 | DIN 7516 |
| M10 | 1.5 | 20.0 | 7.5 | 9.00 | 16~60 | DIN 7516 |
Dimensions are independent of the material: the table above lists the sizes supplied, and on this page every one of them is quoted in A4 Stainless Steel. The catalogue's default material column has been omitted here so it cannot be read as contradicting that.
Custom manufacturing · Made to drawing
Need this screw in a grade that is not listed?
A4 Stainless Steel is one of the grades the catalog describes. Dimensions, material, finish and form are specified from the drawing — a screw outside the standard range is a variation on existing tooling rather than a new design. Made by cold heading or warm forging.
Minimum order from 2,000 pieces; samples within 7 days of drawing approval.
