[TR] Bolt Grade

[John Finlayson]

The following website gives some insight into British bolt grades......

https://www.britishfasteners.com/forum/showthread.php?50-British-Strength-Rating-Codes

An R rated bolt is similar to a Grade 5 according to Curt, the author of the 
post on that site.

John Finlayson
'62 TR4



----- Original Message ----- 
From: "Bob Danielson" <75tr6 at tr6.danielsonfamily.org>
To: "Randall" <TR3driver at ca.rr.com>; "'*Triumphs List'" 
<triumphs at autox.team.net>
Sent: Wednesday, November 03, 2010 8:00 AM
Subject: Re: [TR] Bolt Grade


> And I believe that the unthreaded shank is precision ground which is why 
> driveshaft and axle bolts cost more ($2 each) then standard bolts. They're 
> also harder to find from suppliers other then the usual LBC sources.  I 
> think Randall told me that many years ago!
>
> Bob Danielson
> 1975 TR6 CF38503U
> Running w/ Throttle Body Injection,
> Toyota 5 speed & Nissan LSD
> http://tr6.danielsonfamily.org
>
> --------------------------------------------------
> From: "Randall" <TR3driver at ca.rr.com>
> Sent: Wednesday, November 03, 2010 9:18 AM
> To: "'*Triumphs List'" <triumphs at autox.team.net>
> Subject: Re: [TR] Bolt Grade
>
>>> A friend wants to replace
>>> this bolt with a US equivalent
>>
>> I can't answer your question, Alex, just wanted to point out that there 
>> may
>> be more to that bolt than just grade.  For example, TR driveshaft bolts 
>> have
>> a particular diameter and length of unthreaded shank, and unusually short
>> threads.
>>
>> IMO it's unlikely to be any stronger than SAE grade 5, but that's just a
>> guess.  One way to estimate it is to look at the torque spec.  Standard
>> torque for a grade 5 7/16-20 is 75 ft-lb.  If the specified torque is 
>> less
>> than 75, it's probably less than a Grade 5 bolt.
>>
>> Randall
>> _______________________________________________
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