Conclusion about threads

Do you know what is a thread?

A thread or screw thread is a helical or tapered structure used to convert between rotational and linear movement or force.Screw threads have several applications.But the application that used for water pipe system is to connecting threaded pipes and hoses to each other and to caps and fixtures. In all of these applications, the screw thread has two main functions.It converts rotary motion into linear and prevents linear motion without the corresponding rotation.

This is the topic about the thread that you should to know
1. Type of thread
- Type of pipe thread
2. Material of thread
- Metal
- Plastic
3. Basic profile of thread
4. Unit and standard of thread
- Common unit
- Standard thread
5. Manufacturing of thread
- Manufacturing metal thread
- Manufacturing plastic thread

1. type of threads :In generally there are 2 type of thread, external thread (male) and internal thread (female).the thread that used for water pipe or shower hoses system, also called pipe thread. It can divide into 2 types. Parallel threads, which have a constant diameter (G), and taper threads, whose diameter increase or decrease along the length of the thread ( R).

This is different point of choosing to use the parallel threads or taper thread. Parallel thread used mainly for mechanical connection, it for joint between pipe and pipe or, pipe and hose. It for that part jointing that not much to move, the example using the parallel thread to joint between shower hoses and opening –closing part (a faucet).And using the taper thread to joint between shower hoses and shower head because this jointing part is always to move all time when they are take a bath. The taper thread have pressure-tight more than parallel thread. And they always used a taper external thread, but can have either parallel or taper internal threads.

2. Materials of threads :Material that use for produce threads, there are two main types which are metal and plastic. Metal, there are brass, stainless steel for mainly used. But they are always to use bass to be the thread material because brass have rust resistance quality.
However they are not to choose iron to be the material Plastic is the mostly use to be thread material too because it is cheap cost and easy for production. However from inquired from Cotto company, they told me that The most of shower head part are usually to use plastic to be the material because it have light weight, easy to produce and cheap cost, and the most of plastic that used is ABS. But about the thread part are always to use brass to be the material because it to be durable more than plastic.

3. Basic profile of pipe thread : Basic profile of pipe thread will tell you about basic dimension, tolerances and designation of thread, I think it is important point for industrial designer should to know because industrial designer, who are not just to design product but they can to do technical drawing too. Industrial designer and engineer are always to work together. The example if you are designing the shower or the tap, which is the product that have thread part and then you sent the design to engineer but you don’t know basic dimension of thread, so engineer can’t produce your product.


4.Unit and standard of thread : The unit that use for unit of thread have 2 type, there are inch unit and millimeter unit. The inch unit is mostly use in America and Canada. The millimeter unit is the unit of ISO, British And Japan.

Standard thread is the Standers for machine threads have existed since the mid nineteenth century, to facilitate compatibility between different manufacturers and user.The metric ISO screw thread are the world-wide most commonly used type of general-purpose screw thread. They were one of the first international agreed when the international Organization. For Standardization was set up in 1947.Furthermore, there are Unified thread standard (UTS), which is still in common use in the United States and Canada. It has the same 60 degree profile as the ISO metric thread used in the rest of the world. And British standard pipe thread (BSP) it has 55 degree profile, so now obsolete.

5. Manufacturing of thread : As a result of thread material have metal and plastic, so the process to produce metal thread and plastic thread are different way. Manufacturing of metal thread are normally manufactured by one of three methods. There are Cutting, Rolling, and Casting but they are always use cutting method for produce thread. Rolling and Casting method use for special produce thread. And about manufacturing of plastic thread are normally use injection molding method for produce thread, It is the convenient and fast manufacturing of plastic thread moreover it is the method that can produce many quantity of thread.

Taps and dies are cutting tools used to create screw threads in solid substances including, but not limited to, metal, wood, and plastic. A tap is used to cut the female portion of the mating pair (e.g. a nut). A die is used to cut the male portion of the mating pair (e.g. a nut).

So this is all knowledge of thread that you shouldto know, if you want to design shower, tap, or product that have thread part!

Reference

-Screw and thread book from sanwa company
http://www.wikipedai.com/
http://www.cotto.com/
http://www.nikels.com/

Manufacturing screw threads between plastic and metal

Manufacturing screw threads

We can divide manufacturing of threads into 2 type
-manufacturing metal threads
-manufacturing plastic threads

manufacturing metal threads :
Screw threads are normally manufactured by one of three methods

Cutting: The excess material is removed, with taps and dies for smaller diameters, or with a thread-cutting lathe for larger ones.
Rolling: The material is extruded into a thread through mechanical pressure. Common for high-production threads of diameters typically smaller than one inch. A rolled thread is instantly recognizable because the thread has a larger diameter than the blank rod from which it has been made. The threads of bicycle spokes provide a perfect example. Rolled threads tend to be slightly stronger than cut threads.
Casting: Material is either heated to a liquid (or rarely a gas), or dissolved in a liquid that will evaporate and allow the material to solidify (such as plaster or cement). Alternately, the material may be forced into a mould as a powder and compressed into a solid, as with graphite.

Manufacturing plastic threads :
They always use injection molding for make a plastic thread

Unit and standard threads

Common unit of thread
-Inch : (UTS) the United States and Canada
-Millimeter : ISO, (BSP) British, (JIS) Japan

Standard threads
Standers for machine threads have existed since the mid nineteenth century, to facilitate
Compatibility between different manufacturers and user.

ISO standard threads :
The metric ISO screw thread are the world-wide most commonly used type of general-purpose
Screw thread. They were one of the first international agreed when the international Organization For Standardization was set up in 1947

Unified thread standard (UTS) :
The Unified Thread Standard (UTS), which is still in common use in the Unitedstates and CanadaIt has
the same 60 degree profile as the ISO metric screw thread used in the rest of the world, but The characteristic dimensions of each UTS thread were chosen as an inchfraction rather a round.Millimeter value. This standard include
-Unified Coarse (UNC)
-Unified Fine (UNF)-unified Extra Fine ( UNEF)
-Unified Special (UNS)
-National pipe thread (NPT)

British standard pipe thread (BSP) :
The British standard pipe thread is a family of standard screw thread types that has been
Adopted internationality for interconnecting and sealing ends by mating and external (male)
With and internal (female) thread.

Basic Profile

material of thread

Material of thread

Type of material used for produce thread shower :
-Metal : brass, stainless steel, Chrome plated Brass
-Plastic : ABS, Chrome plated ABS
-Cromoflex