Views: 1788 Author: Site Editor Publish Time: 2022-12-21 Origin: Site
Lubrication System Tube Fittings Use Metric taper external and mating parallel internal screw threads
Whatever straight and elbow taper stud connectors of lubrication fittings, metric external taper thread of M6 keg, M8x1 keg, M10x1 keg, it intended to be mated with parallel internal threads with a basic profile as specified in ISO /DIS 68-1.
Taper external threads as specified in this standard are intended for self-sealing joints, such as those employed on pipe plugs, compression couplings and lubricating nipples. They can be used in all cases wherea parallel threaded joint with washer is unsatisfactory for technical or economic reasons.
For fluids such as oils, other liquids and gases, no thread sealants are required for joints where the nominal size is small. For joints of greater nominal size, it is recommended that sealants be applied, since the leaktightness of such joints decreases as the diameter increases.
A short design taper external thread has been specified along with the standard design both to be mated with general purpose ISO metric parallel internal threads of tolerance class 4H for the pitch diameter and 5H for the minor diameter (as in ISO/DIS 965-1 ).
Design profile of a metric taper external thread
Inspection
In practice, taper external threads are mostly checked using commercial screw gauges. The end face of the threaded portion is pressed against a step in the gauge (tolerance step), and the limits of size of the thread at the gauge plane are determined, disregarding dimensions a and b (since these dimensions may be taken as theoretically exact).
Normally, thread diameters are measured at the gauge plane. However, in order to detect any crowning of the thread, the thread dimensions may be checked at the reference plane (or any other plane along the useful thread I ength).
Gauges should be selected according to the thread parameters that are being checked. For instance, taper screw ring gauges are suitable when checking all thread parameters, whereas parallel screw ring gauges are adequate when only the function of the thread is being checked. In both cases, however, the width of the gauge ring has to be adjusted for the thread design (standard or short). The ring is then screwed on the workpiece and the distance between the end faces of the workpiece and gauge is established. When the ring gauge is provided with a step face, the end face of the workpiece thread is not to protrude beyond this step. (DIN 1 58-2 specifies parallel ring gauges with tolerance steps, in accordance with IS0 1 502.)
Although the incomplete thread of parallel ring gauges must be removed, this may influence the inspection results. For this reason, such gauges are to be regularly checked for wear using taper screw check plugs. Since gauging and measuring threads may lead to different results, there is a risk of rejection in marginal cases. It is therefore recommended that manufacturers and their clients agree on the method to be used. Where no
agreement has been made, results of gauging in accordance with DIN 1 58-2 shall be decisive.
Production Range
Fitsch provide you lubrication tube fittings, with taper metric thread meet DIN 158-1 standards, material is availavle in carbon steel and stainless steel, for more product info, please visit our lubrication tube fittings catalog, also interchangeable into SKF BEKA lubrication tube fittings catalog.
