Knurled rim knobs are made to obtain a firm grip. The small ridge patterns are rolled or cut into the material for a non-slip grip. They come in a wide variety of different styles and are often used on applications where the operator may be in contact with damp or wet surfaces. The knurled rim helps to prevent fingers from slipping to ensure positive tightening. They are also available in a handle form for use with a longer or larger surface area that requires using other directional movements.
The mechanical properties of a molded plastic part may differ considerably according to the particular shape of the part and the manufacturing process used. Accordingly, we decided that it would be important for designers to know the operational stresses that a given part could resist.
Torque resistance tests were performed using a dynamometer text fixture that applied an increasing amount of torque to the part being tested. The torque value (C) is expressed in foot pounds (ft. lbs). Shocking resistance tests were performed by dropping a calibrated weight from increasing heights (4 inches) onto the part being tested. The impact value (L) is expressed in foot pounds. (ft. lbs).
ELESA Original Design, Ergostyle by Elesa
|Thread N/A 10-32||Height N/A 0.71 in||B - Hub Diameter N/A 0.49 in||D - Hub Projection (DS) N/A 0.41 in||U - Tapped Depth N/A 0.39 in||Protrusion N/A 0.01 in||Diameter N/A 0.83 in (21 mm)|
|Thread N/A 1/4-20||Height N/A 0.89 in||B - Hub Diameter N/A 0.57 in||D - Hub Projection (DS) N/A 0.55 in||U - Tapped Depth N/A 0.47 in||Protrusion N/A 0.01 in||Diameter N/A 1.00 in (25.4 mm)|
|Thread N/A 5/16-18||Height N/A 1.06 in||B - Hub Diameter N/A 0.73 in||D - Hub Projection (DS) N/A 0.67 in||U - Tapped Depth N/A 0.63 in||Protrusion N/A 0.01 in||Diameter N/A 1.22 in (31 mm)|