Cross-Recess Screwdriver Bits (PH / PZ) (DIN 3126 / ISO 1173 (C6.3 hexagon drive)) are specified where the joint requires installing, adjusting or servicing the assembly rather than forming part of it. The sections below cover the typical end-uses by industry, the size and material decisions for each, assembly practice, and the applications this fastener type is not suited to. Stocked across roughly 1 to 3, they cover light-duty and instrument-scale work.
Typical Applications for Cross-Recess Screwdriver Bits (PH / PZ)
The most common settings where these are specified:
- General machine building: fastening covers, brackets, motors and sub-assemblies on production equipment.
- Maintenance & repair (MRO): a stocked size for servicing existing plant where the original fastener spec must be matched.
- Fabrication & metalwork: bench and on-site assembly of steel frames, enclosures and weldments.
How to Specify Cross-Recess Screwdriver Bits (PH / PZ) for Your Application
- Size: Select on size designation, and confirm it against the mating feature in the assembly. This product spans 1–3; check the full table below for the exact dimensions of each size.
- Material: Choose the material and finish for the service environment — plated steel for general use, stainless for corrosion resistance.
- Environment: For damp, coastal or chemical exposure prefer A4/316 stainless or a suitable coating; indoors, plated steel or A2 is usually sufficient.
- Standard: This product is supplied to DIN 3126 / ISO 1173 (C6.3 hexagon drive). Quoting the standard on your order guarantees interchangeable dimensions between suppliers.
Where Cross-Recess Screwdriver Bits (PH / PZ) Are Not the Right Choice
Match the fastener to the load, environment and whether the joint must be reopened; the wrong class or style is the usual cause of joint failure.

