The springs will be hardened and then tempered. So I would think that the pin would be softer and designed to wear down! Have you tried to file the old pin?. This would give you an idea of how hard ist is. Out of interest, the bearing area for the pins in the fixed member, is this bushed with a hard bush?, again the pin should be softer then this. I would have though a "tough" grade of steel, is what you are after, "key stock" grade would be OK, but you want a rod not a flat. Unless some one shoots me down, I think silver steel should be OK .

Frank

If you can't get suitably sized high tensile bolts to modify then EN36 steel would be suitable. Colin

I don(t know about Citroens but I have restored a number of 1920s and 1930s cars. Late thirties cars usually use a "Silentbloc" bush and an ordinary HT bolt. Earlier models usually have a bronze bush fitted to the spring and a pin that is case hardened and ground, usually with drilling for grease nipples. It is possible to do the case hardening at home but there may be problems with distortion. The best way is to use a special nitriding steel and get the surface nitrided professionally.

Having said that, I have made pins from EN8 steel and used them for years without problems.

Russell

Just bear in mind that this is a safety critical application. MOT man was grumpy about a high-tensile bolt I made to hold a brake caliper on as he said my hex wouldn't take as much torque as a proper allen socket. Let me off as I said I has a proper bolt ordered (which I did).

Neil

As the spring has a bronze bush you need to inspect it to see if it is worn and needs replacing. An HT bolt as bought will not be suitable as it will be undersize and won't have provision for greasing. You will need to buy or make something like these:

You will note that they are drilled for grease from a nipple that screws into the head. They have a ground finish although a good turned finish, polished afterwards will do. They also have some provision to stop them rotating. This is very important otherwise the shackle plates will wear.

They should be made from a reasonably tough steel such as EN8 (you could,at a push turn them from larger HT bolts)

You might be able to source some suitable steel locally from a machine shop. Look in the Pages Jaunes under "Rectification, usinage, fraisage".

Bon chance,

Russell.

Edited By Russell Eberhardt on 07/03/2013 07:35:51

Niel mentions proper allen socket be carefull when buying allen socket screws or bolts as there are many inferior strengths being marketed I would sugggest get genuine Unbrako if required for a critical job. **LINK**

Paul

Just been thinking :- these are quite big for a car shackle spring pin. Might it be worth looking at heavy goods spare parts for suitable pins ?

Hi Russell,

That sounds like something in the EN19/EN24 range, both available in "T" condition and easily worked in home workshops.

chriStephens

Edit, just remembered that somewhere I have a book that converts K&E steels to these newfangled Emergency Numbers, well it is an old book! If I can find it in a reasonable length of time will post results

Edited By chris stephens on 08/03/2013 17:16:31