Welding Tips and Tricks

So I have a forklift in my small shop and one of the load wheel axles broke. So I decided to make a new axle and was wondering what type of steel I should use. Some info on the axle. It is about 5 inches long, 1 1/2 in diameter. It slides through the wheel bearings into the leg and is held on both ends by the leg plates that are about 3/4" thick. The load wheel bearings but up against the plates so all the weight is focused on the last inch of both ends. Now I could just use some mild steel round stock from the steel yard but I don't know if it's up to the task. Also a friend wanted to know if I would be up to making some for him so I want them to hold up. The forklift wieghs about 6,000lbs. And holds a load of 3500lbs. Has 4 load wheels, a drive tire and a caster wheel. Some steels I have considered are regular steel yard mild steel, A36, 1018, 4140. I would like to find the most cost effective steel since I could be making more of these.

That's the kind of part you need to get from the manufacturer.

Stick the busted axle to your bench grinder and see how hard it is. There are charts available on google if you don't know how to read the sparks.

I'm expecting a pretty hard steel, and if you're making them for others, "cost effective" significantly changes meaning over making one for yourself.

Steve S

That's the thing, they seem to be case hardened and made out of cheap steel, probably Chinese metal. I know they get them made for cheap but the manufacturer charges $50 for an axle because they are the only ones who sell them. I may ha e to do some test of my own and get some different types of metals and make some axles and beat on them to find the right one. Thanks.

For $50 I'd just buy one. If your time's worth anything at all you're gonna be in it more than $50 just in time. Not even counting materials.

If the bearings are self contained ie they have an inner race & the shaft only supports the weight then EN24 ( preferably EN 24T) which is easily available & the T designation allows you to use it without heat treatment - often used for pins on backhoes etc - but if it's the kind where the bearing is a wide needle roller & has no inner race running directly on the shaft which I've seen quite often then to do a good job you want EN36 which is easy to get BUT it can not be hardened in any practical sense at home & would have to go off to a proper industrial heat treatment place where they first carburize so many thou deep prior to hardening ( this material has too little carbon to thru harden & is often used in applications where a bearing runs direct such as in gearboxes where a glass hard outer layer is needed but the core is left softer as it would be prone to cracking under extreme loads.

Thanks for the replies. The bearings are sealed ball bearings and the shaft does not move. It only supports weight. I also got some advise from a machinist and he said a lot of shafts and gears are mild steel that has been case hardened with a compound. I am going to try this and do torture tests and also get some of that steel you just mentioned.

The material your machinist speaks of will likely be EN36 or higher & though has too little carbon to conventionally harden hence the need to carburize is not " mild steel " nor is mild suitable for your purpose - as the bearings do not rely on the surface hardness of the shaft then just a good un-heat treated shaft material should be fine - depending on the load against mounting points & shaft size then anything from EN16 > EN24 should be fine - on a side note - many low stress application half shafts are made of thru hardened EN 24 so if you have access to a junk yard pull a couple from a dead axle that are a bit bigger than you need then normalize / anneal them so machinable - make them to size required on a lathe & re-harden - that's what I do when stuck for a bit.

ldbtx wrote:For $50 I'd just buy one. If your time's worth anything at all you're gonna be in it more than $50 just in time. Not even counting materials.

10-4 on that. $50 for a part that could kill you or someone else? No questions asked. As well, then the liability is on them, not you.