High Tensile Bolts

[Biscuits]

I was reading a thread and noticed high tensile bolts mentioned. With being involved in strong discussions involving raised voices at work, I thought I would make a thread about the blighters.

Firstly, high tensile bolts can be identified by either marks or numbers:

0 lines; Grade 1or2
3 lines; Grade 5
6 lines; Grade 8
then you have 4.6, 8.8 and 12.9 rated
Many people believe you should use HT for any pulling force. But Ht will snap not bend when stressed. I have been advised that HT is for taking strain along the shank from top and bottom, not from side.

But for more info look at these links below I found while making this thread:

http://www.qldcorvetteclub.com.au/te...talk/bolts.htm

http://www.offroaders.com/tech/Bolt-Identification.htm

hope this helps

as an ex fastener rep (nuts & bolts salesman) your very close.

no lines = Mild steel imperial (Metric equivalent is class 4.6)
3 lines = grade 5 HT (Metric equivalent is HT8.8)
5 lines (most manufacturers) = grade 8 HT (Metric equivalent is 10.9)
6 lines = grade 8 ht some manufacturers/ grade 10 very few manufacturers (Metric equiv 12.9)

Most socket head caps screws (allen key bolts) will be 12.9ht or a class 10steel.

I will try and find some of the training manuals I had for the newbies, and post them up if your interested