Bit of a nerdy one really, but when reassembling the rally car, I tend to always use a washer under a nut or bolt, for some reason it looks wrong without. I've loads of custom bits on it, so I'm not always able to reuse the oem fasteners. My question is, am I right, or are washers really only needed when the hole is a bit sloppy for the bolt or is slotted? When I make a bracket myself, and decide to bolt it on with m6 fasteners, I drill a 6mm hole, where oem stuff tends to be more likely a 7 or so. Same for 8, 10 etc. So in my case, assuming the metal is of decent strength, are washers unnecessary? I ALWAYS use locknuts.
Just so the edge of the nut doesn't bind/damage the surface to which it's being bolted to, I suppose it depends on the job it needs to do? Give us an example
OK, typical of the kind of messing I'm at, I had to make my own PAS pump bracket, to relocate the pump and to use a lighter than stock(Ford) one. That's 25mm angle-iron, in mild steel. 10mm Cap screws going through 10mm holes, on a flat surface. I used lock washers, with a flat washer under them, even though tbh the angle-iron's hole is a lot more exact fit than the "off the shelf" 10mm flat washer! Lol. My original question is because of 3 things. One, every washer weighs something, and every kg counts. Two, on event servicing, the bloody things tend to get lost too bloody easily when you take off a nut or bolt. Three, maybe they are no advantage? Sent from my D5803 using Tapatalk
I always use washers wherever possible, no matter the job Always been told this by my Dad and my Grandad! I can't even explain why
A washer can help with multiple things, strength, locking, sizing, vibration etc but i'm sure you know all that. The way i look at the technical aspect of it is the washer allows the head of the bolt to spin. So when tightning a bolt into a tapped hole, the only way to get a true reading on the torque you have applied is by fitting a washer, otherwise you are getting a false reading becuase of the friction between the bolt head and whatever you are bolting to not being able to spin. However, there is no locking function of a standard washer which is why you have to run threadlock on some bolts and not just rely on the torque to hold them in if it's subject to load or vibration. The use of the locking washer helps as you have used in the picture above. I can't see a problem with that. Having just put together the rear axle of my MK5, i had to question VW's thought process on some of the bolt/washer combinations. There is also some funny shape washers in there when i can't see the need for them, a round one would have done the same job! When it came to torquing it up, they use a washer on the nut side as the head of the bolts are serrated on the contact part which they want to "bite" into the part. The washer allows you to tighten the nylok to the correct spec without binding on the product.
I've always thought a Washer was used to spread the load. To give a better hold for the bolt to hold down whatever it was holding.
Oh I agree, just wondering what's the advantage if what you're putting it on it already strong enough on its own.
Tristan it's to do with clamp loading on the material face: in the application you show there, i would propbably use them as cap heads have a smaller footprint than hex (I prefer how they look as well) so you use a washer to spread the load better, bigger washer for softer material to better spread load and reduce subsurface shear and compressive stress other considerations would be if you have alloy to steel to avoid galvanic corrosion. In your example, I'd drill the bolts and lock wire them together instead of lock washers and keep the washers to spread load Sent from my iPad using Tapatalk
