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Westfield Fasteners Product Specification:

DIN 7982, similar to - Square Drive Countersunk Head Self Tapping Screws Type C Point

This product guide contains the specification for metric threaded socket head button screws as available from Westfield Fasteners. The basis of this specification is the DIN standard DIN 7982C.

Product Description
Square drive countersunk head tapping screws are suitable for use with sheet metal and plastics. The square drive makes 'cam-outs' or screwdriver slips less likely, as the driver connects more securely than a pozi or a phillips drive.

As their name suggests, self tapping screws will forms it's own thread as it is installed into a pre-drilled hole.
Scope of the DIN standard.
DIN 7982 specifies the tolerances and the variation in form of countersunk tapping screws, for sizes from No.2 (2.2 mm) up to and including No.14 (6.3 mm). This type of tapping screw has an AB type thread, which is the most prevalent tapping screw thread form on the market. This means that the threads are closer together than other tapping screw thread forms. Another defining feature of these screws is their type C cone point.

Table 1 below defines the overall dimensions and tolerances of this screw type, whilst table 2 defines the tolerances on the shank length.

Figure 1: Square Drive Countersunk Head Self Tapping Screws

Figure 1: Square Drive Countersunk Head Self Tapping Screws

Variations from DIN 7982
The DIN standard DIN 7982 does not mention a square drive as an option, but these screws conform in every other respect.

Table 1: Dimensions & Tolerances according to DIN 7982 (mm)

thread diameter2.
thread pitch, p0.
distance to first full thread, amax0.
head diameter, dkmax=nom4.
head height, k≈ (approx.)
radius under head, rmax0.
length of threaded end, y maxType C22.
S drive---SQ1SQ2SQ2--

Table 2: Shank Length Tolerance according to DIN 7982 (mm)

Nominal LengthType C

For further details, please refer to the ISO/DIN standard document for this item.