and that the Z-design helps prevent premature tip breakage

The BAHCO 4559-18 provides specified cutting capacities for both rebar and harder spring steel and is extensively described on the manufacturer's product page

Hex Profile: 10 mm

Its specified breaking capacity is 50 kA

Nominal cross-section (max): 1 mm² (stated for the product family)

unbrako bit 5/64"x89mm Unit(s):Pcs and that the Z-design helpsProduct Overview The Wera 840 4 Z Hex Plus bit, 05059660001 is a bit for internal hexagon screws (innensechskant). The product is categorized as a bit and is designed for use with holders that accept 1 4" hexagon shafts. Design and Function The bit uses Wera's Hex Plus profile, which, according to the manufacturer, provides larger contact surfaces in the screw head to reduce notching and damage. The Wera 840 4 Z Hex Plus bit, 05059660001 is described