Clearance Hole Data

For optimal seal screw performance, we recommend creating a clearance gap in the panel, into which the O-ring can be fitted. The "squeeze" of the O-ring, and a slightly oversized gap within which it can reshape itself, causes the O-ring to create a complete seal. The clearance hole thus prevents extrusion into the metal when the screw is under pressure. Our extensive selection of screw and O-ring material, coupled with our vast technical knowledge and communications skills, means that we have all the necessary tools when it comes to providing our customers with the very best self-sealing screws on the market. We don’t just provide clients with the generic; instead, we work closely with our clients to learn about their exact, nuanced needs, and then execute production accordingly. To take advantage of the products and services we offer, please get in touch with us today.

Recommended Clearance Hole Data

UNC Max Hole Diameter		Metric Max Hole Diameter
Nom. Size	Max.	Nom. Size	Max.
2-56	.095	M2	2.437
4-40	.127	M2.5	2.946
6-32	.151	M3	3.454
8-32	.177	M3.5	3.656
10-32	.200	M4	4.546
10-24	.200	M5	5.562
12-24	.228	M6	6.655
1/4-20	.265	M8	9.041
5/16-18	.332	M10	11.048
3/8-16	.397	M12	14.045
7/16-20	.467	M14	16.051
1/2-20	.531	M16	18.057

* Please note ZAGO offers an oversized head product line to accommodate a large opening application.

Drive Types
Schematic	Drive Type	Uses
	Combination: Phillips / Slotted	Accepts Phillips and standard blade screwdrivers. Often used when fastener is expected to be driven and backed-out several times.
	Hexagonal Recess	Ideal for precision assembly. Most recommended where less surface area is available.
	Phillips	Most recommended drive type. Provides good control in driving. Always use a driver bit of the proper size which is in good condition.
	Square	Increases productivity with excellent torque transmission and resists cam-out. Distinctive appearance which discourages tinkering.
	6-lobe	Positive-engaging, fast-locating method which transmits drive torque with less required downward pressure. Good fastening appearance.
	Slotted	Accepts standard blade screwdriver. Requires less downward pressure to drive parts than those with recessed openings. Use propert fitting blade to minimize slippage.
	Hex	Accepts hex wrench. Slotted drive is added to make it easier to remove the fastener.
	Slotted Hex
	Hex Flange
	One Ways	These screws are impossible to remove without the special matching screw driver.
	Spanner
	Hex Socket with Pin
	6-lobe with Pin