Products are available from
Inspection rules for DTF-Lock threads
Due to its special thread form, the internal thread of DTF-Lock nut must be inspected with special DTF-Lock plug gauges. The special plug thread gauges are actually a three-member gauge system, including a GO gauge, a ramp NO-GO gauge and P. D. NO-GO gauge. The DTF-Lock thread gauges must enter into the tested nut in the same direction as the bolt.
Table 1 Inspection method for DTF-Lock nuts.
|Name of thread gauge||Series number||Appearance||Operation rules|
|Thread GO gauge||series number R620-TGG||Thread crest is sharp||a. It can be screwed through internal thread of the work piece. *|
|b. If the gauge can pass through the internal thread with some resistance, it can be judged as conforming.|
|Thread ramp NO-GO gauge||series number R620-TRNG||Thread crest is sharp||The gauge can be screwed into internal thread of the work piece, but the engaged length shall not exceed three pitches.|
|Thread P. D. NO-GO gauge||series number R620-TPNG||Thread crest is flat||a. It can not be screwed through internal thread of the work piece.|
|b. If the NO-GO gauge can pass through the internal thread with some resistance, it can be judged as conforming, provided that the resistance occurs before the third thread tooth.|
|For product with surface coatings, if the thread GO gauge can not pass through its internal thread, the product can also be judged as conforming if the GO gauge can pass through it when the surface coatings are removed.|
How to order: R620-DTFLOCK series number - size Example: R620-TGG-M20