Общий каталог FANAR 2021 - страница 309

i Technical information 7.4. Use of gauges and checking of threads Checking of internal taper (Rc) and internal parallel (Rp) threads Stage 1: The taper threaded plug gauge (gauge No. 1) is screwed hand tight into the internal thread. The internal thread is within the permissible tolerance if the end face of the threaded workpiece lies between the step faces, or flush with one of the step faces on the gauge. 1 2 3 3 Key: 1 - end face of work piece flush with tolerance step on gauge, 2 - end face of work piece flush with face of gauge 3 - gauge No. 1 Stage 2: The taper threaded plug gauge with relief (gauge No 2) is screwed hand tight into the internal thread. The internal thread is within the permissible tolerances if the end face of the threaded workpiece lies between the step faces, or flush with one of the step faces on the gauge. 1 2 3 3 Key: 1 - end face of work piece flush with tolerance step on gauge, 2 - end face of work piece flush with face of gauge 3 - gauge No. 2 Note 1 : If a workpiece is rejected by gauge No. 2 but accepted by gauge No. 1, then this may indicate a lack of accomodation lenght. Note 2 : A variation in the relative position of the gauge steps of gauge Nos. 1 and 2 in excess of 0,5P but not greater than 1P is permissible when the manufacturer and purchaser agree that the use of a thread sealant sealant during assembly of the workpiece will compensate for the increased differnce in the gaugin results. Note 3 : In the case of Rp threads, if the depth of chamfer at the pitch diameter of the threads is more or less than 0,5P, then the gauging result will be slightly affected. Checking of external taper (R) threads Stage 1: The threaded ring gauge (gauge No. 3) is screwed hand-tight onto the external thread. The external thread is within the permissible tolerance if the end face of the workpiece lies between the step faces, or flush with one of the step faces on the gauge. 1 2 3 3 Key: 12 1 - end face of work piece flush with tolerance step on gauge,2 - end face of work piece flush with face of gauge 3 - gauge No. 3 306