A4 Stainless Steel Tube-End Threaded Inserts are supplied to our own published dimensions — this is a trade-series article rather than one covered by a dimensional standard, so confirm the figures against the part you are replacing. The grade provides superior, including marine and chloride environments and is largely non-magnetic; the practical service range is approx. -200 °C to +400 °C, subject to the property class and the joint.
Why Choose A4 Stainless Steel for Tube-End Threaded Inserts
Specified for marine, coastal and chemical applications. For tube-end threaded inserts, 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 |
Galvanic & Galling Considerations
Two important notes for stainless tube-end threaded inserts: (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 Tube-End Threaded Inserts, 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 Tube-End Threaded Inserts Available in A4 Stainless Steel
| Tube form | Thread size | Tube dimension / inside diameter (mm) | Insert code example | Retention | Material options |
|---|---|---|---|---|---|
| round tube | M8 | inside diameter 20.5 | ITT2T/M8/19.5 | pressed crown / flange | steel / zinc-plated steel |
| square tube | M6 | 20×20 | ITQ2S/M6/18.9 | pressed crown / flange | steel / zinc-plated steel |
Dimensions are independent of the material: every size above is available in A4 Stainless Steel.
Custom manufacturing · Made to drawing
Need this threaded insert in a grade that is not listed?
A4 Stainless Steel is one of the grades the catalog describes. Thread size, body length, knurl or key form and installation method are all variable against the parent material. Made by tapping or knurling.
Minimum order from 2,000 pieces; samples within 7 days of drawing approval.
