Dodgy bolts

[torana68]

I posted this on a car forum I'm on , might be relevant to some people here


hopefully your all aware but for those with trailers and general info........ Just happened I was in the Bolt shop to replace a Chinese Crankshaft bolt that broke. This was a metric bolt marked 8.8, it snapped inside the crank after 2 hours work. This thing drilled like real soft mild steel, had a chat to the bolt guy and he mentioned the Chinese bolts that are supplied with the Chinese trailer couplings that are out there. These are also marked 8.8 but are an imperial thread , so incorrectly marked for a start. They were also poorly threaded looking to be offset somehow, his opinion , poor quality mild steel rubbish. So I'm saying don't use ANY but confirmed non Chinese bolts anywhere where safety is a concern. Don't know if anyone like Roads and Maritime, or whoever is responsible, will order a recall or care but Id rather not read of an accident on here caused by cheap nasty bolts.

[Kunama]

Those Chinese bolts are everywhere these days Roger,
They are not high tensile though have been stamped so. I have drilled through them easily with a cordless drill and HSS bits.
Best to buy only from places like Spec Fast etc.

[torana68]

I only buy at Specality Fasteners, wouldn't even buy at Bunnings as Im assuming theirs are Chinese for the most part, problem is the unknowing home fiddler who will fit a part to his car/trailer with soft faulty bolts, if he checks he'll see them marked correctly and think all's good, then if he's lucky he may only loose his trailer....

[speach]

I used to sell industrial fastener, and you would be up against it to find any fasteners that are not made in China, Taiwan, India etc, even most Cap screws, they used to be manufactures in UK, aust usa but even them are made in those countries now. We have no Main line manufacture's here anymore. The only advice I can give is to buy from a reputable dealer, were there is a come back if a bolt fails. Do not buy an important bolt form the local hardware store.

[Kunama]

Personally I would rather not see any more threads on IIS about BOLTs unless they are bolts used in telescopes !!! ;)

[MortonH]

:lol: I assumed that's what this thread was about!

[AussieTrooper]

There was an episode of Aircraft Investigations on this topic. Cheap bolts were substituted for the more expensive aircraft grade ones. The tail rudder stopped working, with catastrophic results.

[Wavytone]

At work we had a similar issue with bolts for the brake disks on Tangara trains.

Some twit in procurement thinking any bolt is much like another, and thinking they could save a bucket of money decided to buy unapproved bolts, probably from somewhere like Bunnings. The result is brake disks falling off as the cheap-ass bolts broke fairly quickly under load.

Thankfully an 8-car Tangara train has 32 brake disks, so there is inherently a lot of redundancy, but I can imagine the driver descending a downhill gradient (chatswood to epping tunnel)pulling on the brakes and wondering why it isn't slowing down...

Moral: never... EVER let procurement departments make decisions. They are just itching to try.

[speach]

Why not it's an important issue. You pay $2000-$5000 for a mount, and they mostly come with crap bolts, and then whinge about spending $2.00 on a decent bolt. Go figure!

[RB]

Matt, (Kunama) was joking, it was tongue in cheek, presumably referring to the recent thread discussion about rifles and guns not being related to astronomy on IIS.

[Kunama]

Yes, perhaps I should have used instead the emoticon with its tongue in cheek !:P

[AussieTrooper]

We have the exact same problem at my work. Procurement repeatedly ignore engineers advice and buy chinese rubbish.
In the past, all large scale electrical equipment was designed to work for 40-60 years, (some of it still in good condition after being installed in the 1900s!). Now we are lucky if it lasts 20-30.

[torana68]

I can say its an Australia wide issue when non engineering people try and make engineering decisions or try to overrule engineering staff to save a few $$ or just because they have no idea but are full of "good ideas" its probably why we have rubbish bolts, they are cheap and they are just bolts right? very wrong, were probably getting close to a fatal accident or three ,then , maybe , someone will apply some control on what is sold here. Astronomy wise I don't replace good quality bolts with cheap, don't see the point in saving 50c for a bolt that could cause me grief.

[The_bluester]

Procurement folk even undo their own decisions.

Ours kept on chasing a cheaper supply of fibre optic cable (usually aerial cable)

Every time they changed suppliers the new cable would be a different diameter and all the mounting hardware in stock would become useless.

[jenchris]

The bolt in my gun was pretty poor too......lol
Hard not to indulge my whim... I apologise for any loss of sanity due to frustration.
:D

[RB]

And then you've got the cheap Chinese ammunition you should steer well clear of....

RB

:lol:

[LewisM]

Made me laugh profusely Andrew - thanks :)

[RB]

Yes, me too Lewis.

:thumbsup: