I noticed a small cut(or crack) on my FRW.Its not deeper than 1mm and I do not see any wires nor I have any pressure leakage. Is it ok to keep using them?They are for winter and I am using it only 4-5 months a year.
It's pretty much up to you. But let me tell you something, in a period of my life I was so busy that I didn't have time to change my tires. It was so cut off that you could easily see the wires and I couldn't go above 70mph! The car was vibrating above that speed! Now I don't encourage you to drive in that condition. Especially if you are living in a country where there are heavy rains. But I think you're good to go.
By the way if the cut is not asymmetrical (in one part of one tire) it might be an indication of faulty wheels. You might want to check that up. (A picture of the crack would help)
How long do you think the thread will last on this axle? If your answer is "not a whole lot" or "less than a year" then replace.
If there's a fair bit of thread left, seeing as you've not cut any wires, just keep an eye on it. Keep in mind that the wires are now exposed to the elements so the lifespan of your tyre will be reduced.