Life while installing shelving in my home i had to drill pilot holes for 8 and 12 metal screws into studs.
Pilot drill size for sheet metal screws.
Self tapping screws sheet metal.
Inch approx us gauge material 020 055 26 17 diameter 061 122 16 11 diameter 125 245 11 3 diameter 250 312 3 5 16 diameter 313 500 5 16 1 2 diameter.
Your pilot hole drill bit size will depend on the size of your sheet metal screw.
Types ab b self tapping screws in mild steel brass aluminium alloy stainless steel and monel sheet metal.
It is important that the correct hole size is used and the recommendation below should be followed but if very hard material is being used a hole size slightly larger may have to be used and in very soft material a smaller hole.
Size 6 7 64 inches.
Pilot hole sizes for metal screws and wood screws posted 30 january 2010 at 9 43pm by michael chu filed under.
However there are times when sheet metal screws are required.
For clean precise holes in thin sheet metal make a wood sandwich.
Size 8 1 8 inches.
Drill gauge no to be used for.
Drill gauge no or letter to be used for maximum holding power.
In a single time saving operation these screws drill tap and fasten.
The problem was i didn t know how big to drill the holes and when the holes were too small it was quite difficult to.
There is nothing more aggravating when you just don t know what size drill bit to use for a pilot.
To counterbore for striking head.
Size 12 5 32 inches.
Size 14 1 4 inches 3 16 inches.
For shank clearance holes.
Twist bit nearest size in fractions of an inch.
No of auger bit.
Material thickness inch nominal screw size diameter tpi.
Sheet metal screws 100 our trucks deliver throughout se sw florida to place an order please call customer service at 1 800 226 5555 or fax to 800 582 6110 nominal screw size number of threads per inch 2 32 3 28 4 24 5 20 6 20 7 19 8 18 10 16 12 14 1 4 14 5 16 12 3 8 12 48 46 44 36 32 30 29 21 3 16 5 5mm i 21 64 0760 0810 0860 1065 1160 1285.
To help my readers out i thought i would add this quick reference chart.
Twist bit nearest size in fractions of an inch.
A size 4 screw should have a pilot hole drill size of 3 32 inches.
Do not use self drilling screws in blind holes holes that do not pass through the material.
Simply sandwich the sheet metal between two pieces of wood and clamp everything down on a table or workbench.
This should help whenever you run into a situation you need to drill a pilot hole and are not sure the size bit.
Sizes of 4 40 to 3 8 16 are common.
The wooden bread layers of the sandwich keep the sheet metal flat and prevent the drill bit from wandering as it bores through the sheet metal.
Self drilling screws also called teks have a tip that resembles a drill and often have spaced threads like sheet metal screws.
Size 10 9 64 inches.