Installation and Torque | Resources | ZAGO | Switch Boots, Seal Plugs, Seal Screws, Seal Nuts

With respect to installation and torque, there are three important design calculations and they are as follows:

Percent Squeeze – giving standard torque installation
Compression/Stretch percent
Groove Volume

Since there are wide ranges of sealing applications, more calculations may be required. If you are using standard sealing applications, then the calculations have already been done. On the other hand, if the application is unique, then these calculations will need to be tabulated. IMPORTANT: Calculations must be as accurate as possible to avoid an end result of leakage.

Inches

Nominal Screw Size		Installation Torque
(#4)	112 – 40 UNC – 2A	5 in-lbs
(#6)	138 – 32 UNC – 2A	9 in-lbs
(#8)	164 – 32 UNC – 2A	20 in-lbs
(#10)	190 – 32 UNF – 2A	23 in-lbs
(#10)	190 – 24 UNC – 2A	23 in-lbs
(#1/4)	250 – 20 UNC – 2A	75 in-lbs
(#5/16)	312 – 18 UNC – 2A	142 in-lbs
(#3/8)	375 – 16 UNC – 2A	263 in-lbs

Metric

Nominal Screw Size	Installation Torque
M3	0.6 Nm
M4	2.3 Nm
M5	4.0 Nm
M6	8.5 Nm
M8	18 Nm
M10	36 Nm
M12	60 Nm

* Please note that the above values are recommended average values only. Variations in local conditions and the material may require significant deviations from these recommended values.