Hardness : measuring surface is 58-65HRC, and the hardness of the parts smaller than No. 0.4 is 53-60HRC.
The tolerance zone of the pitch diameter of the “go” end of the American Standard Unified Thread working plug gauge is compressed inward by a gauge manufacturing tolerance value, giving the “go” end of the thread plug gauge a wear allowance.
CUSTOM – MADE
We can supply other sizes of thread plug gages, for example, 1 1/4-16 UN LH
We provide thread plug gages with the following thread tolerance classes: 1B / 2B / 3B / 2B+0.03 .
We also provide thread plug gauges of G series, RC series, PT series, RP series, NPT series, NPSM series, and etc. .
Introduction to American Standard Thread Working Plug Gages:
Purpose of American Standard Unified Thread working plug gauges: To comprehensively inspect American Standard unified internal threads specified in ASME B1.1-2003 and GB/T 20666-20670-2006.
Inspection environment for American Standard Unified Thread working plug gauges: The standard temperature is 20°C ± 1°C, and the measuring force under standard conditions is zero.
Inspection methods for American Standard Unified Thread working plug gauges: The single pitch diameter is detected by the “three-wire method” using a length measuring instrument. The pitch, flank angle, minor diameter, and clearance groove are detected by a universal tool microscope.
Use of American Standard Unified Thread working plug gauges: For the inspection of product internal threads, qualified working plug gauges that have passed the inspection should be used. The working plug gauges should comply with the relevant provisions in the JB/T 10865 standard. To reduce disputes during inspection and acceptance, it is recommended that the manufacturer, inspector, and acceptor use the same qualified gauges. If it is difficult to use the same qualified gauges: A. The manufacturer should preferably use new or less-worn “go” end plug gauges and “nogo” end plug gauges that are close to the wear limit; the inspector and acceptor should preferably use “go” end plug gauges close to the wear limit and new or less-worn “nogo” end plug gauges. B. The “go” (T) thread plug gauge has a full-form thread profile. When used to inspect the effective pitch diameter and major diameter of the product internal thread, it should be able to screw through. C. The “nogo” (Z) thread plug gauge has a truncated thread profile. When used to inspect the single pitch diameter of the product internal thread, the screwing engagement should not exceed two pitches. D. If the working plug gauge used to judge the product internal thread is qualified and complies with the relevant standard, then the product internal thread is considered qualified.
