Size 12 5 32 inches.
Pilot hole size sheet metal screws.
Twist bit nearest size in fractions of an inch.
And 5 16 inches 1 4 inches.
A size 4 screw should have a pilot hole drill size of 3 32 inches.
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.
To counterbore for striking head.
Twist bit nearest size in fractions of an inch.
Drill gauge no or letter to be used for maximum holding power.
It is recommended that you should spend ample time to read and understand the drill bit guide.
However there are times when sheet metal screws are required.
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.
The best way to drill an accurate pilot hole is to have the right hole size.
To achieve this the right bit size should be used.
There is nothing more aggravating when you just don t know what size drill bit to use for a pilot.
For shank clearance holes.
Size 8 1 8 inches.
Lo driv tri round recommended pilot holes sizes metric screws.
No of auger bit.
Aluminum sheet and bar including aluminum andzinc die castings and all alloys in rockwell b hardnessrange from 40 70 and other ductile materials of similar hardness such as brass bronze etc note special materials and applications may warrant special hole sizes.
To help my readers out i thought i would add this quick reference chart.
Average rockwell b 55 75.
Size 14 1 4 inches 3 16 inches.
The pilot hole should be well fitted to the screw or the nail so that it would not wobble when inserted.
Size 6 7 64 inches.
Low carbon sheet and bar.
This should help whenever you run into a situation you need to drill a pilot hole and are not sure the size bit.
Size 10 9 64 inches.
Pilot hole sizes for metal screws and wood screws posted 30 january 2010 at 9 43pm by michael chu filed under.
Bit or drill sizes.
Types ab b self tapping screws in mild steel brass aluminium alloy stainless steel and monel sheet metal.
Your pilot hole drill bit size will depend on the size of your sheet metal screw.