suitable grades of steel???

[philsmin]

I'm sure some of you clever people out there will be able to help.

I need to make some pins for the bottom arms on my minis suspension, I was originally going to get some high tensile bolts and have them machined to suit, however i'm struggling to find some with a long enough shank for my needs.

So I've decided to buy some steel roundbar to make the pins instead and have that machined to suit.

My question is how does something like EN8 compare to an 8.8 HT bolt, i'm not well up on tensile strengths or steel grades and is it a case that the higher the EN number the stronger it will be?

Thanks in advance

 

[Drains]

Philsmin - I can't answer your question but a good old root around http://www.roymech.co.uk/ might help.

As for long bolts, you may have more luck if you look for socket-head bolts/screws. They also come in 12.9 rather than 8.8.

One thing - the number on a bolt denotes the torque it can take (and therefore how much it can stretch without going beyond its elastic limit). En8 (and EN24 etc) are often used because they are hard/ can be hardened and used in wear situations, rather than just done up tight.

TechincAl might have an angle on this, otherwise Snowcat is bound to have wise words to say.

 

[TechnicAl]

The En mumber is no guide to strength. The later specs do but no-one uses them.
En24T has a much higher tensile than en8

other than that ive no idea

 

[hotrodder]

With regards to bolts the first number is nominal UTS, the second is yield strength as a fraction of UTS i.e. a grade 8.8 bolt is 800N/mm^2 UTS with a yield of 640 (0.8 x 800).

EN8 properties here... http://www.kvsteel.co.uk/steel/080M40.html
Something like EN19T is more of a match 'off the shelf' with regards to published numbers like yield etc

Obviously depends on size/how they used but it's not uncommon for car manufacturers to use 10.9 or even 12.9 bolts in some suspension applications. As Drains said you might find some socket head bolts that'd be suitable. What sort of dimensions are we talking about?

ETA http://www.westyorkssteel.com/en19.html, probably overkill for the application

 

[philsmin]

They are to make pins for the bottom arms, i'm not using the original engine/gearbox so I've had to adapt the subframe to suit.

The original pins are 1/2" diameter with the arm rubber mounted to it.

So I need them to be exactly 1/2" diameter so they fit the original bushes, many people use rose joints but I don't like that idea on a road car.

When I think about it the tie rods are held on with a single HT 5/16's bolt and probably have more load going through them than these will

I spoke to the guy whose doing the machining on them tonight and he's going to see what he has in stock

Thank's for the info