In actual operation, often find sometimes use the elastic pad will increase with a flat pad, sometimes not. This is decided by many aspects of. Surface machining surface, parts of the plating or painting antirust processing is not a scratch, not in direct contact with the spring washer. In the operation to add trim pads, prevent scratch the surface damage of taboo asked spring washer in the process of rotation. If you are connecting piece material hardness is low, so when the connection to increase flat pad, to increase the stress area, to prevent the contact surface damage due to clearance and connection is loose. For the rough surface of unprocessed should first flat pad, or because of uneven surface and elastic pad not to loose proof effects. To play the role, the elastic pad is close to the nut or nut. Problems sometimes installation space, difficult to contain relatively large flat pad. If the surface is now connecting piece No scratching taboo, and the surface roughness and the material is hard, you can not use a flat pad.
