Straight answers to the questions buyers ask us most often about standards, grades and stainless behaviour. Written by the people who pick the orders.
Choosing a grade or a standard
- DIN 933, ISO 4017 and GB/T 5783 — what actually differs
The three designations describe the same hexagon head, fully threaded bolt. Four things decide whether you may substitute one for another, and one of them is not negotiable. - A2-70 or grade 8.8? Picking a fastener for the environment it lives in
Grade 8.8 carries more load; A2-70 never rusts. How to choose between them, what hydrogen embrittlement has to do with your plating choice, and where galvanic corrosion bites. - Why stainless fasteners seize — and how to stop it
Galling is cold welding, not cross-threading. Six practical measures that prevent it, and what to do when a fastener has already locked up.
Before you order
- How to order — the whole path from finding the part to clearing customs.
- Frequently asked questions — minimum order, price, discounts, shipping cost, dispatch, payment and claims.
- DIN / ISO / GB / GOST equivalents — the cross-reference table for the standards we stock.
- Materials and compliance — what each grade is, and what documentation we can supply.
- About SFX Fasteners — the stock, the inspection and the packing behind the catalogue.
- All fasteners by specification — every material, size, grade, finish and standard in one index.
Cannot find the answer?
Ask us directly — info@sfxtec.com or the quote request form. Questions about a specific part are usually answered the same working day.