Extra large flat head
Hexagonal shank
Open

Extra thick flat head
Short hexagonal shank
Closed

Stainless steel
Flat head
Semi-hexagonal shank
Open
With lock in the thread

Flat head with two cross flats
Round shank
Open

Flat head with small diameter spacer (guide)
Splined shank
Open

Extra large flat head
No deformation chamber
Splined shank
Open