The Rusty Nut Bible: How to Undo Seized, Damaged or Broken Nuts, Bolts, Studs & Screws

The cheapest parts for vehicles, bikes, boats and buildings are the ones you can reuse. But one stubborn bolt or screw can be a disaster. The three most common bits of advice are: heat it until it glows red, use a longer spanner and use a grinder. All of them might work but they all risk damaging the part, the building or vehicle under repair, and possibly even you.

We've designed a simple, effective, 10-step freeing system to:

• Preserve expensive, rare, or irreplaceable parts;
• Protect existing structures from brute force damage;
• Minimise collateral damage and the risk of injury;
• Save time waiting for replacement parts;
• Save money on parts and labour.

We also cover what to do if things have already gone wrong:

Handling Head damage:

• External drive heads (hex, bihex, square, etc.)
• Internal drive heads (Allen, Torx, spline, etc.)

Handling Thread damage:

• External (shaft) thread repair and replacement
• Internal (bore) thread refurbishment and repair

HandlingSheared or snapped shafts:

• Protruding stump extraction
• Flush with surface extraction or removal

Extensive Appendices on:

• Basic Tools
• Specialist Tools
• Personal Protective Equipment (PPE)
• The Six Simple Machines

EXTENSIVELY UPDATED

• NEW Web Link Resource
• Improved Readability
• Enhanced Diagrams
• Triple Jump Chapter Indexing

The hazards of Internet wisdom: heat it, use a longer spanner, grind it off.

Heat: Works well for a nut on a bolt because the nut circumference expands, making the hole bigger. It also disrupts the rust crystals. But what about a bolt seized in a bigger item like a brake caliper? Expanding the bolt will disrupt the rust a bit, but that's about it, the bore won't get bigger. Some items are designed to act as a heatsink to keep the things cool. You'll need a very powerful, danergous heat source.

All this assumes there aren't inflammable liquids, flexible hoses or painted surfaces nearby. But vehicles are awash with flammable liquids and tend to have flexible hoses in the very places most likely to get rusty... brakes, exhausts and transmission components. Buildings always have varnished, painted surfaces and even plastics everywhere.

Longer Spanner: This is the least likely to work. It usually ends one of two ways: rounding off at least two corners of the nut or bolt head, or shearing the bolt shaft. This assumes you even have room for a huge lever... or a small lever with a length of tubing threaded onto it and a heavy friend hanging off it!

Grinder: The nuclear option. You accept you'll have ground-off bolt stump to extract, possibly paintwork to repair, and you grind the nut or bolt head off. As with the long spanner this assumes you have enough space for a large spinning disk next to the bolt. Also, showers of sparks and hot metal aren't a great combination with flammable liquids. In cramped spaces you may find yourself unable to slide the assembly off the stump without fouling on something else... You could have spotted that earlier, but when you're frustrated enough to reach this point, you generally don't.