1965 Nut/bolt/washers

[MiNiKiN]

The bolts that pass through a mini bonnet hinge with the brass washers also have a split washer . You can do them up hand tight and open the bonnet a hundred times and the bolt will not come loose . Same goes for the boot lid straps . Now take off that spring washer and I will guarantee the bolt will come loose and the nut will fall off . Therefore to my way of thinking the split washers do work . …. Shirley

The technical reason behind that is that these bolts are technically to short. For a bolt to not come loose you need LENGTH so that the right torque (actually the resulting pre-load) slightly stretches them (below yield point usually) - this is what prevents fasteners coming loose.

If you tighten them hand-tight you are not tightening them. There is basically no clamping-force given. So to use this as an proof pro split washers is unfortunately nothing more than a fallacy. It only proves the spring washer works as a protection against loss of the nut.

So fasteners, which have not been torqued beyond their yield point, can securely be re-used a couple of times. This particularly applies for 8.8 (grade 5) tensile strength fasteners.
I tend to renew 10.9 (grade 8) though - because of their usually applied higher torque figure.

The fastener needs to look mechanically sound of course to qualify for re-use.

[Peter Laidler]

While we were on our fixtures and fitting phase at Uni - and all that goes with it - and ever since, my understanding regarding bolt/screw length (as minikin states above) was that any thread that extends through a nut is redundant.

We are getting into over egging the cake now....... or over thinking the engineering of our simple mechanical heat machines

[Spider]

I rarely agree with Peter But in this case, I do. I cannot imagine any circumstances when I'd choose to use ratty old used fasteners. If I am doing a resto, I would NEVER think of reusing them, re-plated or not.

While I did get loads of the old fasteners re-plated a while back, I don't bother anymore, except for the odd ball fasteners, some fittings and stuff I make.

I agree that there's many quality general fasteners out there, that look every bit the same now as they did in 1965 that it really makes it a fruitless exercise.

What ever parts you may have plated though, be sure to de-gas them afterwards. The cleaning process can induce a hydrogen embrittlement, heating them after plating to about 150 degrees for 15 - 20 minutes de-gases them.

[gazza82]

Moss-Europe sell a bulk pack of nuts, washers, bolts, etc .. 400 pieces of various sizes and lengths.

https://www.moss-europe.co.uk/hardware- ... fk200.html

[richardACS]

Some useful points of view - thanks to all. And the offer Mark.

Plating fixings is a complete P.I.A, and would definitely be happy to forgo the process.

In the past I've purchased fixings from my local factors and have been 'get me by's' and actually work out very expensive - they have been materially less substantial (particularly the nuts), in their depth/length than the originals) and just look wrong - also sometimes the bolts/screws are too long (against the originals) an over long bolt just looks wrong, to cut them down means the ends will go rusty.

However the nuts shown from 'Moss' packs look closer to the originals, I'll order a pack and see how they come up.

The self tappers are right buggers to find replacements, wrong head shape/length and width!

[gazza82]

Try Bresco for self-tappers and other strange things ...

https://www.bresco.com/cgi-bin/ss000001 ... TION=Go%21

[agricola]

A bolt is a fastener whatever its doing you dont want it to come loose. Old nuts and bolts can and do stretch. Original they were normally grade "s" what was known as high tensile or equivalent to modern 8.8 newton bolts. Now replacement with modern 8.8 should be ok but a lot of it is subject to bulk buying overseas, nothing wrong with that except for poor quality control. Some recent metric stuff I've used is like rubber! So for minis I use SAE grade8 which is equivalent to 10.2 N not because you need the extra strength you don't but because QC is much much tighter and they are very nicely plated. Not as cheap might not look quite right but if bits don't come undone.....???