Most bolts unscrew by turning anticlockwise, or to the left. To loosen a bolt, turn it to the left, or anticlockwise, whilst holding the nut in place with a spanner or a pair of pliers.
If you're having trouble loosening a bolt, try using a penetrating oil first to see if this loosens the nut. You could also try hitting it with a hammer to break it loose first, then unscrew it with a spanner.
You can also use a wrench to help you turn the nut first. Finally, if all else fails, you can try using a bolt extractor.
4 Tips for loosening a nut and bolt
Use a wrench to hold the bolt steady while you turn the nut.
Apply lubricant to the bolt and nut to help loosen them.
Use a heat gun to heat up the bolt and nut to expand them and make them easier to loosen.
Try using a bolt extractor if all else fails.
When screwing in a bolt, you want to turn it clockwise, or to the right. This will cause the bolt to tighten. If you're using a wrench, make sure that you're holding the bolt steady while you turn the nut. If the bolt is tight, you may need to apply lubricant to help loosen it. You can also try heating up the bolt with a heat gun, which will expand the metal and make it easier to loosen. If you're still having trouble, you may need to use a bolt extractor.
Try Penetrating Oil to Loosen Nuts & Bolts
Sometimes the bolt may have become stripped, in which case there are other ways to loosen a stripped bolt. Read more here.
If you’re looking to replace your old bolts, Fixabolt sell a range of nuts and bolts in stainless steel and zinc plated.