Twin Hole Security Screws

Special twin pin driver

Machine Screws

 

Technical / Size Guide

click here for technical guide to screw head sizes & drilling guide (357kb PDF file)

Twin Hole tamper resistant security screws (also known as Snake Eyes or Pig Nose Screws) have two small holes drilled into the head. A special twin pin driver bit is required to both tighten and release the screws. The screws are manufactured from A2 stainless steel and are suitable for internal or external use.

The screws are available as Self Tappers in Countersunk Head and Pan Head formats, and as Machine Screws with Countersunk Head, Pan Head or Raised Countersunk Head. All are available in box quantities of 100.

Self Tappers      stock sizes      Countersunk Head         Pan Head

Length >	3/8"	1/2"	5/8"	3/4"	1"	1 1/4"	1 1/2"	2"	2 1/2"	Driver  Size
Gauge /Size	9.5mm	13mm	16mm	19mm	25mm	32mm	38mm	50mm	63mm
4   2.9mm										TH3
6   3.5mm										TH 4
8   4.2mm										TH 5
10   4.8mm										TH 6
12   5.5mm										TH 7
14   6.3mm										TH 8

Machine Screws   stock sizes    Countersunk      Pan Head      Raised Countersunk

Length >	6mm	10mm	12mm	16mm	20mm	25mm	30mm	35mm	40mm	50mm	Driver  Size
M 3											TH 3
M 3.5											TH 4
M 4											TH 5
M 5											TH 6
M 6											TH 8

We also offer a limited range of UNC/UNF sizes commonly used on computer systems.

back to Security Screws and Fastenings index