Please suggest if I did it correct mounting of 100kv brushless ?
Bit difficult to tighten it as the groove is not similar to  the traditional screw has
How to tighten it?

How to mount this motor on the cross mettle part ?
Is it with those black screw shown in first photo?
How to secure from part once the prop is put ?

@iwincar
1. How to mount this motor on the cross mettle part ?
Ans: Like this (see pic)
2. Is it with those black screw shown in first photo?
Ans: Yes
3. How to secure from part once the prop is put ?
Unable to understand the question 

Seems like the screw is longer than the thread in the motor. using a shorter screw or washer might help tighten the hole.

Ashok.P

@iwincar
If you have a 100kv motor, i would like to buy it or give you a motor of your choice from my stock.

I see that you have posted 2 threads. I suppose they relate to the same motor mounting problem.
(It is better to stick to one thread for one issue)

Did the mount (X shaped) and the screws (black) come with the motor, or from some other source?

Did you not get a manual, or at least a piece of paper, with the motor, giving specs and mounting details?

From what you say it looks like the thread in the screws is different from that in the motor backplate. If so, forcing the screws in will spoil everything beyond reasonable repair.

Suggest you share the problem with a knowledgeable modeller in your area.

On the forum there is a risk that persons like me (without knowing the full details) may give you half baked answers, creating more problems instead of solutions. Partly because your posts are either not clear or lack detail.

I could perhaps assist if i knew what the real problem is:
1. Black countersunk screws too long
2. Black screws thread differs from thread in motor backplate
3. How to mount motor to mounting plate
4. How to mount to model
5. Motor and mount/screws from different sources

Blame my lack of understanding!

K k Iyer here are the spec
It's a 1000kv motor sorry for that
No manual or paper in it
It came as packed along with motor prop holder
How can I secure the prop in that holder without the screw I wonder.
Qn is whether to use these screws to secure the prop or on the back side of the motor to mount it on metal cross
&use new set of screw to mount the total unit ie Motor+metal cross on the piece of ply thx

V2eagle it's in non tighten position as I was unsure about it and waiting for prob to be solved
I have encountered two sets of problem.
1.mounting a motor on Metal cross part
2.mounting the combined unit ie motor+metal cross on plywood piece to go on plane

@iwincar,
1. Small black countersunk screws that come with the motor are for fixing the metal cross to the back of the motor.
2. To mount it on the ply plate / nose block of the model, you have to provide 4 screws or nut/ bolts of suitable size. These do not come with the motor.
3. Prop goes on to the threaded portion of the prop adaptor and is held on by the spinner nut in front.
4. The back of the prop adapter has something called a taper collet. Has a hole and four slits. The hole should match the diameter of the motor shaft.
5. Mount prop on adapter, keeping the spinner nut a little loose.
6. Mount this assembly on to the motor shaft. Push it in as far as it can go.
7. Tighten spinner nut using an Allen key or a piece of cycle spoke. This makes the taper collet grip the motor shaft. No other screw etc required.

Hope the attached photos clarify the picture.

@kkiyer can't explain how much that answer helped me thanks a lot ,cleared all my doubts hats off