TIMco Carriage Bolts & Hex Nuts - 12.0 x 220mm - Box of 10 - Silver - 12220CB

Yes, they feature a zinc finish which provides protection, though for harsh or constant coastal environments, additional protective coatings are recommended.

While not strictly required for the bolt to hold, using a standard M12 washer is recommended to distribute pressure and prevent the nut from sinking into the wood.

The head diameter for this M12 bolt is 30.00mm.

Yes, you can cut them using a hacksaw or angle grinder, but ensure you dress the cut thread afterward so the nut can still be applied.

Yes, these carriage bolts are supplied complete with the matching hex nuts.

Grade 4.8 refers to the carbon steel tensile strength. It is a standard classification suitable for most general timber construction tasks.

Ensure the square shoulder is fully seated in the timber. Use a mallet to tap the head firmly into the wood.

Check that the hole is free of debris and that you are using a sharp 12mm drill bit. Avoid forcing the bolt as it may damage the timber fibers.

Check the thread for any debris or wood shavings from the installation process. Clean the threads and re-align the nut carefully.