I must be missing something...when I go to my local industrial
supplier, they only have 2 kinds of 'inch' bolts... UNC and UNF ! All
my taps and dies are the same. What's different about SAE?? Or is that
a U.S. term for a world standard?
I bought new UNF grade 8's for the crossmember... Ran a long tap
though... No problem at all...reused those nice thick stock washers
though...
Also, I don't see a need for those 'long thread' 3/8" UNF bolts for
the fulcrum pins... If you reach into the crossmemer, you can feel all
that extra thread sticking through the threaded backing plate... Just
use shorter bolts with the normal length thread and they will still
stick out the back a little...
Jim
B382000446
Sent from my iPhone
On 2010-07-14, at 4:19 PM, "Would U. Believe"
<mcdangerous@verizon.net> wrote:
> Here's a dumb question: Since these bolts are such oddballs in the
> US,
> what's to stop people from using a 1/2-20 SAE tap and just
> installing new
> Grade 8 SAE 1/2-20 bolts? Just curious. If that's an insane idea,
> is there
> a source for suitable and appropriate replacement crossmember bolts
> anywhere? Thanks. M
>
>
> On 7/14/10 10:57 AM, "Smit, Theo" <Theo.Smit@dynastream.com> wrote:
>
>> Good question! I re-read the various standards (at least as
>> described by
>> Wikipedia) and combined with the Alpine parts reference cited
>> earlier I don't
>> think that these are British thread after all.
>>
>> BSW (British Standard Whitworth) in 1/2" has a 12 thread pitch,
>> while BSF has
>> 16 threads per inch. We know that the chassis bolts are 1/2-20. UNF
>> is spec'ed
>> at 1/2-20 while UNC is 1/2-13.
>>
>> So the question that remains is, are these bolts made with a 60
>> degree thread
>> profile or not? If they are, are they designed for an interference
>> fit (which
>> might explain why a standard die will remove material from the bolt
>> threads)?
>>
>> As already stated, these bolts have a longer threaded section and
>> shorter grip
>> length (thanks Mayf!) than a standard SAE bolt, so you can't easily
>> go to your
>> local ACE hardware store to buy replacements. Using a thread die to
>> put extra
>> threads on a store bought bolt is dangerous because it causes
>> stress risers at
>> the root of the threads - conventional bolts have the threads
>> rolled into
>> them, which essentially forges the threads into the bolt and
>> strengthens the
>> threaded area.
>>
>> Theo
>> ________________________________________
>> From: tigers-bounces@autox.team.net [tigers-bounces@autox.team.net]
>> On Behalf
>> Of Carmods@aol.com [Carmods@aol.com]
>> Sent: Tuesday, July 13, 2010 3:07 PM
>> To: tigers@autox.team.net
>> Subject: [Tigers] Crossmember Installation Headache
>>
>> Jul 13, 2010 09:52:38 AM, Theo.Smit@dynastream.com wrote:
>>
>> they're British fine thread which is almost but not quite the same
>> as SAE:
>>
>>
>>
>> Theo,
>>
>> Are you sure those bolts are British Standard Fine Thread (BSF)?
>>
>> What size are they?
>>
>> John Logan
>> _______________________________________________
>>
>>
>> ---
>> ---
>> ---
>> --------------------------------------------------------------------
>> ---
>> This e-mail and any attachments may contain confidential material
>> for the sole
>> use of the intended recipient. If you are not the intended
>> recipient, please
>> be aware that any disclosure, copying, distribution or use of this
>> e-mail or
>> any attachment is prohibited. If you have received this e-mail in
>> error,
>> please contact the sender and delete all copies.
>>
>> Thank you for your cooperation.
>> ___________________________
_______________________________________________
Tigers@autox.team.net
Donate: http://www.team.net/donate.html
Archive: http://www.team.net/archive
Forums: http://www.team.net/forums
|