Why are "locking washers" necessary when bolting two pieces of wood together?

Question

What would happen if I didn't use one? I'm bolting together pieces of wood and do not have enough clearance to use a washer and a locking washer - how bad would that be?

Answer 1

PlainJane offers some valid suggestions. Lock washers are designed primarily for PARTS that are likely to move in some way, or vibrate. Since we don't know any details about the two pieces of wood you want to bolt together; it may be a useless effort to LOCK the nut to the bolt.

Another answer suggests countersink, which is also a valid suggestion. Lock nuts can also be used, but again, without knowing your intent; any and all advise here might be considered.

Steven Wolf

Answer 2

You have good advice so far but there are some things missing. I'd cut oversize then glue. It cuts down on weight and work. Make sure both faces are very flat. Glue is not meant to be used as a gap filler and if you do then the join is weak. You will need to use a jack plane or router and straight edge. Hold a straight edge against it and peer through where it touches. If you see light, then plane (or use a scraper) on any high spots. Look at the end grain. It wil be curved most likely. Choose the orientation so that the curve in one board opposes the curve in the other. This will minimise warping. If, however, one or both boards are already warping, then join them so the gap is inside, not on the ends. The clamps will pull the join together in the middle and the tension on the ends due to the warp will hold the ends together. You will need several clamps. Spaced out about 8 inches apart. Use these to hold the joint closed overnight. Don't use excessive pressure otherwise you will squeeze out all the glue. If you have a long solid bench, then line the bench with greaseproof paper and clamp the work to the bench. This will make it nice and straight and flat. Otherwise you will need to sandwich the boards between scraps of wood so that a) the clamps don't dent the wood, and b) a larger surface area is under pressure. If you don't have clamps, but do have a bench ( or floor ) then place heavy weights on the top. You can use buckets of water or sand or sand bags etc. PVC glue can be painted on. Epoxy will probably need to be put on with a scraper. Wash PVC coated brush in water. Assuming you use PVC glue, remove the excess glue now (where exposed) with a damp cloth - it's much easier than when it's dry. If you use epoxy, then scrape it off before it dries. I'd recommend the slow drying epoxy as clamping up might take longer than it takes for the quick set stuff to go off. Similarly, if the weather is hot, then even PVC glue can start drying too quickly so consider using a slow drying bond. In any case, slow drying bonds as a rule of thumb tend to be stronger than accelerated bonds. When dry you can cut to size and run a planer or belt sander over the wide faces.

Answer 3

Not as important as on metal installations, like gates, parts subject to vibrations, etc. The suggestion to use a 'locking nut' is right-on" it's a nut with a plastic or nylon insert that resists the bolt from loosening. You can also use LocTite...but choose wisely: there are 2 types of it, one is removable, the other is permanent.

If the wood is thick enough, you could countersink a hole just deep enough to accommodate a lock-washer, flat washer and the nut.

Answer 4

Try using a flat washer. This will keep the nut and bolt from drawing itself into the wood when you tighten them.

Answer 5

you don't need locking washers, not in the uk anyway, but it is advisable to put some form of jagged edged washer between the two timbers on every bolt, it helps prevent any movement between the two timbers. and between the nut and the timber it is also advisable to place a large washer. this is purely to prevent the nut drawing into the timber to far when tightening...

Answer 6

Buy a lock nut. They have a couple different types. Using it with the fender washer will be all you need. Locktite will work but is way more expensive than a lock nut. If you only need one lock nut just buy that instead.

Answer 7

Lock washers hold pressure on the nut so it won't loosen, if you left them off you possibly might have to tighten them occasionally not a big deal. An alternative elastic stop nuts they never loosen or rarely.