Meyer Gage 60 Degree 4 TPI English Thread Measuring Wires, 4 Pitch

• Each wire diameter is matched to the others within +/- 0.000001"
• The diameters of the three wires shall be within 0.00002" of the calculated best wire diameter
• All measuring wires include the actual wire size and the constant required in determining the pitch diameter
• Made in U.S.A.

Meyer Gage Thread Measuring Wires are superior to that specified by the most demanding of Federal standards. The roundness of Meyer Gage Thread Measuring Wires is assured by 100% inspection. All Meyer Gage measuring wires meet former Federal Specifications GGG-W-366b, which for identity of size, taper and roundness requires a tolerance of.00001" for Grade A Wires. Identification: Wire sizes are nominal. Calibrated size will show on label with matching constant. In all cases the calibrated wire diameter will be within +/- 10 millionths of the exact size of the wires and within +/- 20 millionths of the nominal best wire diameter (G), as specified for Grade A Wires. These wires are the best sizes for standard 60° inch and metric threads. They may be used with other thread forms or with special pitches, constants for which may be calculated from the formula shown below. They are made from selected high speed steel, are extremely accurate in roundness and straightness and are within.000020"of exact size. The formula for determining wire constants for all 60° threads = 3W -.866025P. Where W = wire size and P = Pitch (1/T.P.I.) The most accurate and universally recognized method obtaining pitch diameter measurements of thread plug or setting plug gages is by means of using three hardened steel measuring wires laid into opposite sides of the thread. Precise measurements with proper pressures over these wires minus the appropriate constant equals the measured pitch diameter.