Hi I hve a 1995 BMW 525I and planning to replace the sprk plugs need to know if I have to use some kind of lubrecant on the sprk plug threads and what will be the torque value, Thanks.

Spark Plugs:

Electrode Gap 0.7 - 0.8 mm

Tightening Torque M14x1.25 30+/-3 Nm 30+/-3 Nm

This is a dry torque: no lube should be applied, but a small dab of anti-seize would be appropriate.

Dear CaptainRich, I didn't undresatnd what is this value for I have a torque wrench it is Inch/Pound so what should I set this to, Thanks.

With changing ANY plug, whether it is on a old beat up Ford Pinto or a 800,000$ car, the same rule applies to all of them. ONLY tighten them hand tight, no torque wrench needed. If you OVERtorque or overtighten them, you could strip out the threads in the heads and have to replace the heads because of this, or you could break the spark plugs themselves, so just turn them until they are tight with the ratchet and stop.

Really but I am told that it should be torqued and needs a torque wrench, Thanks.

Dear CaptainRich, I didn't undresatnd what is this value for I have a torque wrench it is Inch/Pound soo what should I set this to, Thanks.
30 Nm is equivalent to approx 22.1 ft lbs.
Online Conversion - Torque Conversion (http://www.onlineconversion.com/torque.htm)

That is pretty light torque and generally an experienced tech can judge "hand-torque" through repetitive usage. Though not exact, it is often reliable, in experienced hands.

Here's what I would do if I had to take mechanics '101' all over again. Turn the treads down till they stop. Now, 1/4 turn more. That's it! Not too tight, and definitely not loose.
A nice light coating of anti-seize on the threads is an extra plus due to dissimilar metals.

Thanks to all