Bolt Markings

[dazzler]

Hi all

I have a left of field question.

Does anyone know what these markings on the head of a bolt mean.

IE strength etc.

It is a metric thread (M12) 100mm long and is bright coloured (I would normally call it zinc)

It has the following markings
B

D2

M or a W

cheers

The other bolt is shorter, black and has an 'x' and 8.8 which I take is a metric high tensile.

Cheers

[.RC.]

8.8 is the grade

It goes..

4.6
8.8
10.9
and 12.9

[azzrock]

the 8.8 does mean high tensile.not shore what the other marking are probably a brand. i think its safe to say that bolt is not high tensile

[Big Shed]

See table 10 in this link for tensile markings

Metric Bolt Properties, Grades, and Strength (http://euler9.tripod.com/bolt-database/22.html)

[Metalman]

Big Shed,
Whilst I don't disagree with the writers sentiments in your reference, the last few sentences in paragraph 'i' are a bit out of place in a technical article.
Mm.

[Dave J]

Mn,
Totally agree, I guess he doesn't like the US.

Dave

[dazzler]

Thanks all!

B, D2 and M just got thrown at the neighbours cat....bullseye :2tsup:

[Pete F]

Big Shed,
Whilst I don't disagree with the writers sentiments in your reference, the last few sentences in paragraph 'i' are a bit out of place in a technical article.
Mm.

Given the references he uses I believe he is an American, and there are a lot of US citizens basically smacking their foreheads with their hands as to what's going on with their country. Obviously there's more to it than just their collective reluctance to accept and embrace global change instead of dictating it, but it's certainly frustrating and I guess this is just an opportunity to vent.

For bolt head identification, once again, The Engineer's Black Book is a very handy reference and shows the various markings.

Pete

[electrosteam]

US Metric,
Metric design was specified on a elevated/subway passenger railroad contract for Philadelphia that I worked on in New York (upstate) 1993 - 1998.

The car structure and bogie design were done in Dandenong, all car bodies and about 14 complete bogies were manufactured in Dandenong.
The US factory did the rest.
I drove the elevated/subway operator crazy when I investigated their cross-sectional car clearance diagram to determine just where the 3rd rail collector should be positioned.
They had no drawings, so I commissioned a metric one for them and presented it for approval.

The US design office was interesting, the CAD guys persisted with US dimensions (decimal inches, not imperial fractions) being added to the drawings.

I believe metric dimensions were referenced in some way in the US Constitution.

John.

[jack620]

What happens when you get your metrics and imperials mixed up:

Gimli Glider - Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/Gimli_Glider)

and:

http://articles.cnn.com/1999-09-30/tech/9909_30_mars.metric.02_1_climate-orbiter-spacecraft-team-metric-system?_s=PM:TECH

[19brendan81]

Ha ha..paragraph i) is a beauty!