Design Anzor Quick Drill Screws to Eurocode 5, AS1720 & NZS AS 1720.1:2022

Anzor is 100% New Zealand owned and operated and has supplied stainless fasteners and fittings for over 30 years, from 12 branches nationwide. Quick Drill is its timber construction screw line, supplied in 304 stainless steel, 316 stainless steel and in NanoGalv coated carbon steel, with star drive heads in countersunk and washer forms.

Four Anzor Quick Drill families are integrated for New Zealand, all under ETA-12/0471. Every family is partially threaded with a star drive.

• 304 Star Csk PT Anzor Quick Drill Screw. 304 stainless steel, countersunk head, T17 tip, 6-10 mm, 80-200 mm
• 304 Star Washer PT Anzor Quick Drill Screw. 304 stainless steel, washer head, T17 tip, 6-10 mm, 80-360 mm
• 316 Star Csk PT Anzor Quick Drill Screw. 304 stainless steel, countersunk head, T17 tip, 8-10 mm, 80-200 mm
• 316 Star Washer PT Anzor Quick Drill Screw. 304 stainless steel, washer head, T17 tip, 6-10 mm, 80-200 mm
• Nano Galv Star Csk PT Anzor Quick Drill Screw. NanoGalv coated carbon steel, countersunk head, with tri-claw nibs, 6-10 mm, 80-300 mm
• Nano Galv Star Washer PT Anzor Quick Drill Screw. NanoGalv coated carbon steel, washer head, with tri-claw nibs, 6-10 mm, 80-360 mm

Nano Galv (VG AF) is a coating with a zinc base layer and an epoxy topcoat, as specified in the ETA. Tri-claw nibs are available only on the Nano Galv range. Outer thread diameters are 6, 8 and 10 mm and lengths run from 80 mm to 360 mm. Characteristic values are held per article in the integrated database and read at calculation time rather than interpolated.

The integrated families support:

• solid timber, glued laminated timber and cross laminated timber, all of softwood;
• laminated veneer lumber of softwood;
• timber-to-steel connections;
• insertion at an angle to the grain;
• exposed conditions, held for service class 3.

For laterally loaded screws the effective diameter is the outer thread diameter, in place of the 1.1 times thread root diameter rule of EN 1995-1-1 clause 8.7.1(3). Embedment strengths are still taken from EN 1995-1-1.

Screws of 8 mm and above driven without pre-drilling require the member to be spruce, pine or fir, and Douglas fir members need the spacings and distances parallel to the grain increased by 50%.

Head pull-through applies only where the head diameter is at least 1.8 times the shank or inner thread diameter, otherwise the assessment sets that capacity to zero; both head forms clear the limit at 6, 8 and 10 mm. In steel-to-timber connections pull-through is not governing.

Cross laminated timber carries its own conditions: the outer thread diameter must be at least 6 mm, which the whole range meets, the inner thread diameter must exceed the widest gap in the panel layer, and plane surface spacings are 4d parallel to the grain, 2.5d between rows, 6d to either end, 6d to a loaded edge and 2.5d to an unloaded edge.

All four families are available in the Screw module and in the connection detail calculators: panel-to-panel (half-lap, spline and butt joint), slab-to-wall, wall-to-wall, floor-to-wall. They are also available in the rib-deck calculator, for flexible connection design to Eurocode 5.

Design is to EN 1995-1-1 clause 8.7 for screwed connections, with clause 8.7.2 for axially loaded screws, and both the 2004 and 2025 editions are supported. Clause 8.7.2(1)P lists withdrawal, pull-through, tensile failure and buckling under compression among the failure modes to be considered, and ETA-12/0471 supplies the parameters for those checks. The certificate is issued and supports CE marking. An ETA is a European assessment; the same product data is used for design in the Australia and New Zealand market in accordance with the applicable design standards there.

For New Zealand projects, Anzor’s updated Quick Drill brochure provides technical information based on NZS AS 1720.1:2022. Anzor confirms that this compliance applies to the 304 stainless steel, 316 stainless steel and Nano Galv ranges. The Eurocode 5 guidance above and the New Zealand design guide use different design provisions; use the guide applicable to the project.