Belleville Washer Minimum Torque

Tightening torque values are calculated from the formula t kdp where t tightening torque.

Belleville washer minimum torque.

Flat loading a belleville disc spring helps to ensure that bolts do not loosen while machinery is in use. Thread friction coefficients have theoretical values. Torque tension reference guide printed in u s a. So that the bolt and belleville washers work together make sure the torque for your belleville washers matches that of your bolts.

These washers have smaller outside diameters than standard spring lock washers to fit neatly under socket head cap screws. A belleville washer also known as a coned disc spring conical spring washer disc spring belleville spring or cupped spring washer is a conical shell which can be loaded along its axis either statically or dynamically. And p bolt clamp load developed by tightening. In threads per inch 307a astm a307 grade a sae j429 grade 5 sae j429 grade 8 f n l g 9 fnl grade 9 clamp load lbs tightening.

If you exceed a locking washer s torque by more than a few percent during assembly you destroy the locking washer. Should you have any additional questions our engineering team here at belleville international is available for your convenience and can be reached by calling 877 235 5384. Belleville spring lock washers also known as conical washers these have a slightly cupped shape that gives them spring like flexibility to grip tighter than split and tooth lock washers. When tightening according to guidelines and with no deviation this is the pre stress achieved expressed as of yield point.

Again belleville washers are no exception. Torque is the rotational force applied to a bolt to tighten a belleville disc spring. D nominal bolt diameter. The belleville washer can then be added seamlessly and no modification to this torque value is needed.

This is the same with belleville washers. A belleville washer is a type of spring shaped like a washer it is the frusto conical shape that gives the washer its characteristic spring. G f ratio of yield point. Cu c paste copper graphite paste molykote 1000 oil wd40 has been used.

The belleville will be in its flat position when the preload in the bolt equals the flat load1 since the spring will be clamped between the flat joint an d the nut any additional torque applied to the nut will only stretch the bolt. Flat load is the amount of axial force required to flatten a belleville disc spring. Forces are decreased as m ore washers are used in series since some of the contact. Clamp load lb is calculated by arbitrarily assuming.

μ th thread friction coefficient μ h under head friction coefficient 1 n 0 225 lb 1 nm 0 738 ft lb. Clamp load is also known as preload or initial load in tension on bolt.