Using Hammer Frame Fixers For Exterior Door

[Mother Goose]

Hope someone can help with this as its beginning to frustrate me as to what I am doing wrong.

I have built a new exterior door frame and door and they both fit inside the frame space in the rear wall of my house. The problem comes with fixing the door frame to the wall. I have purchased 10mm x 100mm hammer fixings and have drilled a 10mm hole through both the door frame and the sandstone blocks beyond to a depth longer than the fixing.

The trouble is when hammering in the fixings. They go 3/4 of the way in then lock solid and any further heavy hammering starts to buckle the head of the screw. Sometimes the nylon plug slips into the hole as well which doesnt help as it has to be drilled out before starting again.

I've been putting the nylon insert all the way into the hole flush with the frame then putting in the screw. Is this right or should I leave it pre-assembled.

I thought these things were just tapped home with maybe a final tightening with the screwdriver? Or should they be hammered or just screwed? Somethings not right here. Can anyone shed some light here

 

[ModernMaterials]

you iant sposed to separate em

but if you manage to get the plastic bit all the way in.. you should screw the screw in and not hammer it cus with the plastic bit being all the way in, your hammerrring is just buckling it up under the screw