Is it correct?

You're using two subjects in your sentence, so I imagine the correct version would read:

"These rounded, headed screws would not give stability due to there projection."

Then again, I (personally, for what it's worth) would reword it anyway for clarity...

AnonymousThese rounded headed screws would not give stability due to its projection.

The grammar is correct.
In the US we have flat head screws, round head screws, pan head screws, oval head screws, hex head screws (lag screws), and probably some others.
Pan head and oval head may be described as "rounded head." Of course "round head" may be thusly de

These round-headed screws will not provide stability owing to their projections

The projections of these round-headed screws may not give stability (to the structure/something).

You sentence lacks enough clarity to provide any suggestions.

Thank your for your swift reply

This is a freestanding display piece. Since the base of the unit is having round headed screws, we can't keept it as freestanding poistion. We need to ask the supplier to remove the screws because of these screws would not give stability due to the projection.

Got it!
If the base is wood, it would be easy to counterbore for the round heads, or to countersink for flat head screws. Flat head screws can easily be driven in flush if the wood is soft.

I assume the base has several screws. If the heads are sticking out, flat head screws won't really give you much more stability.

A metal base can also be counterbored or countersunk wit