i have been reading about tempering in a home oven but was wondering about what temperature should it be done at for rail road spike knives?

Works good but don't let the wife see.

If it's a so-called "high carbon" spike, it only runs abuot 0.3% carbon. That's very low for a knife -- only moderately hardenable even in a really severe quench. Don't bother tempering it.

Go to Goodwill and buy a good toaster oven for five bucks and put it in your shop. No domestic quarrels!

Matt is correct... full hard is fine for spike knives.

I have an old Black Angus toaster oven in the shop.
I use it for tempering anything from a knives and chisels to power hammer dies.
I check temperature with an IR fluke thermometer.

When my wife got a different stove for the kitchen, (50 year old propane range), I got the old electric one for the shop. So once I get power out there I can not only temper but brew tea, heat soup, etc.

I temper in our electric fan assisted oven at 200ºC (although 01 blades do look a little blue at times), suspended on disposable BBQ trays in the middle of the oven. I tried at 190ºC due to the bluing, but they stayed very brittle so were too hard.
All seem to come out OK at 200ºC ,and hold an edge put on with a Lansky System.

I agree with Matt even a RR spike stamped HC on top will be fine a full squelch. The other idea about the toaster oven is also great. I have 2 at all times. Yard sales, flea markets or thrift shops are great places to pick them up cheap. I don't use the house oven because I squelch in a oil-pariffin mix and it stinks as it cooks off. Hope this helped.

I have one issue with the idea of leaving a HC RR spike at full hardness, and not tempering it. The first spike knife i made, broke, since then I have tempered them all. I have never had another on break on me. this might me a coincidence, or an odd, higher Carbon than normal, spike I had. I don't really know, but I'm taking no chances as most of my free material is RR spikes.