Page 706 - Mastik®

Internal drives for screws Design guideline

– Technical progress and economic factors have resulted in the increasing replacement of slotted head screws by other internal
drive systems.
– It is very important today to take into account the most frequently used drives and their possibilities in design, logistics, procure-
ment and assembly.

Cross recess H (Phillips) according to ISO 4757
– The Phillips cross recessed head is the world’s most widely
used system.

– Has a conventional cruciform recess with all walls inclined,
the end of the screwdriver having trapezoid webs.

– The general dimensions are given in the product information
in the catalogue.

Cross recess Z (Pozidriv) according to ISO 4757
– The Pozidriv cross recessed head is used principally in Europe.
– The four «tightening walls» of the cruciforme recess in contact
with the screwdriver when tightening, are perpendicular. The
other walls are inclined. This can improve assembly if the re-
cess production is reliable. The Pozidriv screwdriver has rect-
angular webs at its extremity.

– The general dimensions are given in the product information
in the catalogue.

Hexagon socket
– Screws with hexagon socket head have proved their worth in the machine and ap-
paratus construction fields.

– The width across flats of hexagon socket head screws is smaller than the WAF of
hexagon head screws, permitting more economic design with smaller sizes.
– The general dimensions are given in the product information in the catalogue.

Hexalobular socket acc. to ISO 10664
– The notion of a drive with hexalobular sockets are a decisive step in developing drives
better adapted to manual and automated assembly. This drive is becoming increas-
ingly popular throughout the world.

– Compared to drives like cross recesses and conventional hexagon sockets, this sys-
tem is characterized by a lower risk of deterioration and a lower pressure force re-
quirement. The typical «cam out» slipping of the tool has hence been eliminated and
the force transmission improved.

– The general dimensions are given in the product information of the respective cata-
logue group.