Bautech International

Technical Data

METHOD OF STATEMENT FOR THREADING COUPLER

XI. Thread Requirement of Steel Bar

1. The thread of end shall be inspected in accordance with the sizes shown in Table – 3

Axiality deviation between end thread axial line of steel bar and the axial line of steel bar is 0.5mm

The pitch and thread length of end thread of steel bar shall be measured with special measuring tool.

The threaded end of steel bar shall be measured with standard thread ring gauge. It should be smooth and appropriate in tightness with pass end.

The transversal crack and scale of threaded end of steel bar: allowance depth <0.015d +0.1, maximum value 0.4mm. The transversal crack and scale of threaded end of steel bar is not more than 3 strips.

The short tooth in threaded end of steel bar is allowable:
a - The range of short tooth of end face circumference: 1/3
b - Allowance tolerance of thread diameter: ≤ 0.15H x 2 1/3
c - Circumference of threaded end < 1/5 length, < thread length 1/2, allowance
<0.25H

XII. Matters Needing Attention for Operator of Threading Machine

The structure of threading machine is more complicated than that of cold extrusion press, thus it is difficult relatively for the operator to grasp the performance of the machine. It is operated by the operator in combination of automatic control and manual control. It is necessary to pay attention to operation so as to prevent machine from damaging, even to prevent human from injury.

When starting up the machine in idle operation, the engine oil or lubricating oil must be added in oil hole, point and surface.

The slide carriage should run for three times forward and backward and more times in the winter. Not only it is operated until it is confirmed that everything is ready normally.

The workpiece should be clamped firmly in the holding device. The tool-close should be in place. It is ensured that the products are accepted.

In accordance with the thread diameter, three steps should be taken in readjustment of tool: a. First for large one; b. Second for small one and c. Moderate; After readjustment, three micro-adjusting screws should be fastened to prevent them from loosening.

Tool-close should be in place. After returning, the tool carrier should be closed in place. The screws of locating rod for positioning device shall not be fastened. The sizing plate should be in dead point to avoid striking the locating point when starting up the machine.

In penetration of tool, it is necessary to select the locating point without over force. Don’t strike the stopper to prevent the slide block from damaging. However it is required to feed in size , or the tip of tooth shall be crude, resulting in discard.

The cutting time is very important. If too early, the thread length is inadequate. If too late, the thread length is too long not to meet the position of tool feed (i.e. as it is not to feed tool, the machine moves backward.)

When changing the change wheel, the power supply should be cut off to shut down machine. It is necessary to leave a clearance between meshing gears. With manual operation, it feels movable. The quadrant nuts should be fastened.

It is necessary to grasp the fit tolerance range for threaded end and coupler. The size of threaded end is in relation to the material, cutter and adjusting ring.