What is the use of Three wire method ?
The accurate measurement of thread pitch diameter, which may be perfect as to form and lead, presents certain difficulties which result in some uncertainty as to its true value. The adoption of a standard uniform practice in making such measurements is, therefore, desirable in order to reduce such uncertainty of measurement to a minimum. The “three-wire method” of measuring thread pitch diameter, has been found to be the most generally satisfactory method when properly carried out, and is recommended for universal use in the direct measurement of thread plug and thread setting plug gauges.
How to Calculate Pitch of screw unsymmetrical threads?
Pitch of screw unsymmetrical threads calculator uses Screw Pitch of Unsymmetrical Threads = (Pitch Diameter of Unsymmetrical Threads+Wire Diameter of Unsymmetrical Threads*(1+cosec((Large Angle+Small Angle)/2)*cos((Large Angle-Small Angle)/2))-Micrometer Reading of Unsymmetrical Threads)*(tan(Large Angle)+tan(Small Angle)) to calculate the Screw Pitch of Unsymmetrical Threads, The Pitch of screw unsymmetrical threads formula is defined as the distance from a point on the screw thread to a corresponding point on the next thread measured parallel to the axis of the thread. It is represented by the letter p. (p=1/n). Screw Pitch of Unsymmetrical Threads is denoted by Pu symbol.
How to calculate Pitch of screw unsymmetrical threads using this online calculator? To use this online calculator for Pitch of screw unsymmetrical threads, enter Pitch Diameter of Unsymmetrical Threads (Du), Wire Diameter of Unsymmetrical Threads (Gu), Large Angle (a1), Small Angle (a2) & Micrometer Reading of Unsymmetrical Threads (Mu) and hit the calculate button. Here is how the Pitch of screw unsymmetrical threads calculation can be explained with given input values -> 2990.078 = (0.00699+0.00166*(1+cosec((0.00872664625997001+0.003490658503988)/2)*cos((0.00872664625997001-0.003490658503988)/2))-0.03566)*(tan(0.00872664625997001)+tan(0.003490658503988)).