Simfix field journal Guides and challenge Built for better buying decisions

The Fix

Practical guides and a fastener challenge for choosing stainless screws, bolts, nuts and washers with confidence.

Guides Play challenge
Guides Find the right fastener advice. Grade choices, standards, head types, drive types and pack-size decisions in one place. Challenge Play the Fastener Finder Challenge. Test your eye for heads, drives, grades and stainless fastener details. Arcade Take on Fastener Frenzy. Pick stainless parts, complete job cards and dodge rusty rejects.
Stainless steel nuts, bolts and screws on a workbench for A2 and A4 grade comparison

Featured guide

Stainless Steel A2 vs A4: Which Grade Should You Use?

Plain English guide to choosing between A2 (304) and A4 (316) stainless steel fasteners. When marine grade is worth it, when A2 is fine.

Read the feature

Choose by problem

Not sure what to read first?

Grade choice Should I use A2 or A4? Specification What does DIN or ISO mean? Pack size When should I buy bigger? Visual match Which head or drive is this?

All posts

Every guide from The Fix.

All316a2a4beginnerboatsbulkbuying-guide

Still choosing?

Browse the guides, play the games, or ask Simfix when the spec gets tricky.