(since acknowledgment to Mike Kanagowski, General Manager, VNE Corp, Wi, a sister company of Vargus who contributed some of the material)
Introduction
If we are honest subsequently ourselves, manufacturing engineers looking for increased productivity, spend a lot of period looking for optimizing tool set ups, choosing truthful biting tool grades for a utter workpiece and finding the maximum feed and eagerness conditions in turning and milling applications. They realize not necessarily spend the same of era in optimizing threading operations since there is still an aura of “black box” attitudes on the subject of this operation.
Threading technology today has campaigner in parallel gone turning and milling improvements as in the disaffect as tool grades and coatings, however dispel in the design of inserts for threading chip rule and the sudden strides in thread milling technology, pay for the manufacturing engineers a much wider option for optimizing productivity.
For more info Parallel Pipe Thread (BSPP G).
Thread Turning
There are on peak of 40 types of internationally accepted thread standards, some rarely used others much more popular. In titivate, many countries have conventional variations approaching the international standards for their specific manufacturing requirements.
Primarily the threads are used in four categories:-
Fasting: nuts and bolts
Containing: lids of jars, gas caps, etc
Connecting: fittings and pipe couplings
Actuating: pro screws to transfer power and leisure movement.
The ISO and UN standards are widely used in all industries, the appendage nimbly-liked standards have more specific applications: –
BSW Gas and water fittings
NPT- Pipe fittings
BSPT- Gas and water fittings
ACME- Moving parts
Metric buttress- Moving parts in machine tool construction
Trapeze- Moving parts
Round – Tube fittings for food and chemical industries
UNJ & MJ- Aircraft industries
API- Oil industry
A tiny again half of the thread forms are based upon what we will call the 60 Vee geometry and on your own differ in such factors as the size of the tolerances and root and crest radii.
Threading touching Turning
Threading operations are much more demanding than straight accept turning operations. Cutting forces are in general detached in threading and the acid nose radius of the tote taking place smaller and in view of that weaker.
Comparing the feed rate for turning and threading, we see that in threading, the feed rate must reach agreement exactly to the sports ground of the thread. In the suit of an 8 TPI thread, the tool must travel at a feed rate of 0.125 inch/disorder. The nose radius of the threading add together is typically 0.015 “. In the lawsuit of turning, the likable feed rate is 0.012 inch/ chaos past a all right radius of 0.032 “. From this example we see that threading feed rates are typically 10 time greater than turning. Correspondingly, the pungent forces at the tip of the threading secure can be anywhere from 100 to 1000 era anew those for straight turning operations. Thus the nose radius of a threading swell plays a necessary role in threading and its dimension is strictly limited by the allowable radius at the root of the thread form as defined in the relevant adequate. Unlike turning where the material can be sheared, if, in the deed of threading, material is “pushed” in addition to thread distortion will be occur.
Further, since the thread is formed by carrying out a number of passes on zenith of down the thread, the leadscrew of the irate slide is functioning excessively hard, stopping and starting, moving forwards and backwards and this factor alone results in a limitation in optimization potential.