What does DIN 7504N mean?

DIN 7504 is the European standard for self drilling screws with a tapping screw thread. N is the head form: pan head with a cross recess. The international version is ISO 15481. An H on the end means a Phillips recess, which is what these are.

Which driver bit should I use?

PH2 for 6G, 8G and 10G screws. PH3 for 12G. Use a variable speed drill driver, not an impact driver.

What are pan head self drilling screws used for?

Ductwork and trunking in 6G, since most of it sits under 1.75mm. Partitions, light gauge framing, shelving, racking and enclosure panels in 8G and 10G. Pan heads sit proud, so use countersunk where something seats over the fixing.

Pan Head Self Drilling Screws

Pan head self drilling screws fix sheet steel to steel without a pilot hole. The point cuts the hole, the thread taps in behind it, and the screw pulls up in one pass. Our range runs 6G to 12G, 13mm to 70mm, bright zinc plated, made to DIN 7504N.

What thickness of steel will these screws drill?

Each gauge has a minimum as well as a maximum thickness of steel they can drill through, and the minimum catches people out.

Gauge	Diameter	Steel Thickness
6G	3.5mm	0.70mm to 2.25mm
8G	4.2mm	1.75mm to 3.00mm
10G	4.8mm	1.75mm to 4.40mm
12G	5.5mm	1.75mm to 5.25mm

Under the minimum, the point punches through before the thread reaches metal and the screw spins. Over the maximum it overheats and jams. Count every layer: 1.5mm sheet on a 2mm section is 3.5mm, so a 10G.

Driving them without stripping the hole

The standard's own drive test runs 6G to 10G at 1,800 to 2,500 rpm and the 12G slower, at 1,000 to 1,800. If a 12G is spinning without biting, that is usually why you’ll need to lower the speed.

Keep steady pressure on while the point is cutting, then ease off as soon as the thread engages. If you keep leaning on it, you will strip the hole you just made.

If you have self drilling screws in front of you and no packaging, measure the fluted section at the tip. That length is roughly the most steel the point will clear before the thread catches up with it. Treat it as a ceiling and err low.