Tag Archives: black roller chain

China Chunky 18K Gold Plated Thick Cuban Chain Black Resin Shell Bracelet Stainless Steel Square Black Shell Cuban Bracelet for Women bush roller chain

Model Quantity: JDB257165-BK
Jewelry Major Content: Stainless metal
Bracelets or Bangles Kind: Chain & Url Bracelets
Gender: Children’s, Men’s, Unisex, Women’s
Primary Stone: none
Jewelry Type: Bracelets, Bangles
Event: Anniversary, Wonderful low cost screw air compressor 12 bar meet the technical requirements Engagement, Gift, Social gathering, Wedding, Informal/Party/Gift/Sporting
Plating: Gold Plated
Shapepattern: Geometric
Style: Punk, Services Robot high precision hub servo wheel motor 5inch 24V 150W 3N.m 270RPM IP54 CZPT brushless gearless dc motor Fashionable/Holiday/Trend
Inlay technological innovation: NONE
Key word: bracelet
Color: Gold
Testing: Lead,cadmium,phthalates totally free,meet common
OEM/ODM: Of course
Design and style: Color Heart Coin Allure

Details Pictures Chunky gold control website link bracelet. This trendy type is your best assertion piece. You can wear it by itself or layer it with othergold bracelets. A best addition to your jewelry collection!

15 12 months OEM/ODM Expertise, 4500 CZPT 310bar Compresor De Aire Pcp Large Pressure sucba diving Air Compressor for rifles de aire comprimido welcome to contact us to customise your very own sytles
NEW ARRIVALSBest Marketing925 SILVER JewelleryGOLD Loaded Jewelry
Elegant JewelryImportant CHAINHAIR Add-onsSuper Discount
Advocate Merchandise About Us Provider On-line:Welcome All Clients From All In excess of The Planet

chain

What to look for in a roller chain

There are many different factors to consider when purchasing a roller chain. One of the most important factors is tensile strength, which represents the force required to break the chain. Roller chains are available in three different tensile strengths: minimum, average and ultimate. Each strength reflects a different limit to the load the chain can handle. However, these limits are not always equal and you should be aware of the differences between roller chains.

Canonical chain

Most roller chains have standard sizes printed on the side panels. This is usually “40” or “C2080H”, but can also be the letter “B”. If the chain is old, it will need to be cleaned to see its size. You can find the size on the standard roller chain size chart, but not everyone is marked. To determine the size, measure the diameter and pitch of the chain, then compare the results to the chart to see what size you need.
Heavy-duty roller chains are available with heat-treated pins, side plates, and rollers. In addition to being heat treated, they are also factory pre-stretched, which reduces wear on these parts. If properly maintained, they can last for years, reducing the risk of failure or corrosion. Depending on the application, standard roller chains are available in different sizes. It can be purchased separately. There are several options to choose from, depending on the size and strength of the application.
PEER roller chains contain solid rollers to reduce shock loads on the sprocket teeth. Heat treating and preloading all components of the PEER chain helps minimize initial elongation. Hot-dip lubrication ensures complete lubrication of all chain components, extending their life and reducing maintenance costs. For heavy-duty applications, ASME/ANSI-B29.1 chain is a good choice.
Standard roller chains are made of steel or alloy steel. However, it can be made of other materials such as stainless steel. In addition to steel, stainless steel is often used in food processing machinery where chain lubrication is an issue. Brass and nylon are also sometimes used. However, they are not that popular. Therefore, you should always check with your supplier before purchasing. By comparing the tensile strength of two different chains and making an informed decision, you can get the best price and service.

Chain without bushing

Bushless roller chains have advantages over conventional roller chains. Unlike conventional chains, bushless chains have extensive lateral flexibility, which increases the chain’s lubrication flow. The inner plates of bushless chains have protruding shoulders so the oil can flow through them more easily and efficiently. This is an important characteristic of a smooth-running chain. Additionally, bushless chains may have improved shifting performance.
The strength of a bushingless roller chain is measured in terms of tensile strength and fatigue strength. The former measures the load a chain can withstand before breaking. Fatigue strength is equally important, and factors that affect fatigue strength include the steel used to make the chain components, the pitch hole fabrication, the type of shot peening on the chain, and the design and thickness of the chain. For example, if the chain is too thin, it may not be enough for heavy-duty applications.
Like traditional roller chains, bushingless roller chains have two different types of links. The inner link has two inner plates connected by pins, while the outer chain has two outer plates held together by bushings. A bushingless roller chain is similar to a traditional chain, except it eliminates a step in the assembly process by stamping the tube into the inner plate. So if you want a smoother ride, a bushingless roller chain is a better choice.
There are two different sizes of bushingless roller chains. One size is designed for use with standard single-strand chains, while the other size is designed for use with double-strand or triple-strand chains. Bushless chains are generally shorter than conventional chains, so they can fit in tighter spaces. Bushless chains are made of the highest quality materials. These chain attachments are case hardened for optimum strength and durability.

Mute chain

The silent roller chain has a smooth, low-noise drive. They are made of stacked rows of flat chainplates with a gear-like profile that meshes with the sprocket teeth. Each chainplate is attached to a corresponding sprocket, which also allows the chain to bend. While these basic components are the same for every silent roller chain, there are many variations that allow them to be used in a variety of applications.
The most popular high-speed transmission, silent chains feature gear-like sprockets. They can be made from single or multiple strands of material. Single-strand chains are less expensive than multi-strand chains, but they tend to wear out faster if not lubricated. Single-strand roller chains can be used for years without lubrication, but for your application, wide silent chains are still worth considering.
The design and construction of silent chains make them ideal for conveying a wide variety of products. They have flat, heat-resistant surfaces. They are also durable and non-slip. They are available in a variety of pitch sizes, widths, and mounting styles. Whether you need chains for general purpose conveyors or glass bottle transport applications, we have you covered. Ask about the benefits of silent roller chain conveyors.
Inverted tooth chains are another option for quieter chains. These chains are designed to reduce noise from engine-related friction. Silent chains are more common, and manufacturers have fallen in love with them. A silent chain consists of several links connected to the sprocket teeth. Teeth rotate to reduce noise, vibration, and chord action. These are the main reasons why silent chains are so popular.
chain

ANSI chain pitch

To measure your bike’s chain pitch, you can use a caliper. This measurement is taken from the center of the rolling pin to the center of the next rolling pin. Chains come in many sizes, but ANSI is the most common chain standard in the United States. A caliper is handy if you’re not sure which size to buy, as it allows you to check for worn sprockets.
Chains that meet ANSI standards will be characterized by a certain pitch. This measurement is based on the width and spacing of the roll. The spacing is usually greater than the width. The standard number will be the right number for the width of the chain or the left number for the rollers. The number on the left indicates whether the chain is lightweight or heavyweight. Heavyweight chains are designated by the suffix “H”.
Common chain sizes are based on ANSI chain pitch. Pitch is the minimum distance between bushing and sprocket. The smaller the chain pitch, the greater the total distance between the two points. This means the chain will last longer. However, if you are buying a chain for a specific application, you should check the pitch carefully as it can affect the performance of the chain.

Roller chain wear measurement

The purpose of roller chain wear measurement is to prevent breakage by monitoring the strain on the chain. There are several ways to measure roller chain wear. The first is to remove the chain from its working position and measure the distance from the sprocket to its measuring end. Another way is to measure the pitch of the chain or the distance between two pins. This method is superior to other methods because it is convenient and accurate.
When measuring the wear of a roller chain, it is important to note that the elements of the chain will gradually deform. About 3.75% of the total wear will be on the pins and the rest will be on the internal links. These wear measurements will vary based on the nominal pitch of the chain and the amount of friction the chain is experiencing. Proper lubrication between pins and bushings, load and frequency of articulation all affect wear rates.
It is important to measure the amount of wear on the roller chain to avoid excessive machine failures. The longer the chain runs, the more wear it will wear. Although the length of the chain should be less than the center distance, the excessive load will cause premature wear. Therefore, lubrication is essential. Additionally, the sag of the chain should not exceed 2% to 4% of its center-to-center distance. Finally, check for unusual noise or visible defects. A common cause of excessive roller chain wear is the size of the load. Every chain manufacturer sets a maximum workload for its product.
There are several ways to measure roller chain wear. If using a high-speed drive, it should have at least 11 teeth, and a medium-speed drive should have at least 25 teeth. Also, be sure to check the length of the chain, even if you should. The same goes for the pin diameter, which should be the same or different pitch as the roller chain.

China Chunky 18K Gold Plated Thick Cuban Chain Black Resin Shell Bracelet Stainless Steel Square Black Shell Cuban Bracelet for Women     bush roller chainChina Chunky 18K Gold Plated Thick Cuban Chain Black Resin Shell Bracelet Stainless Steel Square Black Shell Cuban Bracelet for Women     bush roller chain
editor by Cx 2023-06-27

China Custom Promotion 13mm Black Lifting Chain Hoisting Chain bush roller chain drive

Product Description

Promotion 13mm Black Lifting Chain Hoisting Chain

 

G80 load chain specifications:

Size(mm) Inside Width(mm) Outside Width(mm) Approx Weight KG/M W.L.L. Ton Test Load KN B.L. KN
6 x 18 7.5 21.0 0.79 1.1 27 45.2
7 x 21 9.0 24.5 1.07 1.5 37 61.6
8 x 24 10.0 28.0 1.38 2.0 48 80.4
10 x 30 12.5 35.0 2.20 3.2 76 125
12 x 36 15.0 42.0 3.10 4.6 109 181
13 x 39 16.3 46.0 3.80 5.0 128 214
16 x 48 20.0 56.0 5.63 8.0 192 320
16 x 49 24.5  59.5 5.71  192  320 

G80 load chain display:

 

Company Profile.
 
HangZhou CZPT Hoisting Machinery Plant. was founded in 1999 in HangZhou. Its main development and production facility in HangZhou, offers future-oriented solutions with chain systems and components for a wide range of applications. 
 
We specializes in manufacturing standard heavy duty lifting chain (4MM -12MM), including European Standard chain for rigging, electric block chain and also undertake other special standard chain. Each lifting chain we produced was inspected by our experienced technician who had over 30 years research and producing lifting chain experience, and we also use strict quality control testing system to ensure the products’ stability and durability.
 
Jiazhong’ s primary purpose is produce heavy duty and more reliable lifting chain for lifting application to achieve superior performance and usage, withstand more abuse, high abrasion resistance, greater lifting load. Each bundle of raw materials come with alloy steel quality inspection report issued by the steelmaker, including the component analysis, production date, produced CZPT number, and so on, to ensure the traceability of each batch of raw materials.
 
As the second largest chain manufacturer, our other hoisting machineries have a huge cost advantage. For hoisting, moving, pulling, driving and conveying, our CZPT lifting means, CZPT hoist chains, CZPT Chain block and CZPT Electric hoist are a guarantee of quality, innovation and safety.
 
In Tradition of Dynamic Innovation “that is in the tradition of a modern and dynamically growing family organization, the CZPT Group has officially been nominated as a Hidden Champion of the 21st Century because we are in our defined sectors CZPT leader in quality and technology.

 

 

Usage: Drag Chain
Material: Alloy
Surface Treatment: Oil Blooming
Feature: Heat Resistant
Chain Size: 1/2"*3/32"
Structure: Welded Chain
Customization:
Available

|

Customized Request

chain

Choosing a drive chain for a belt conveyor

The drive chain is used to move heavy objects on the conveyor chain. Chains are magnetic, antistatic, high temperature, or chemical resistant, depending on the application. These types of drive chains are used in many different industries. A common machine that uses this type of drive is a chain hoist. Chain hoists are designed to lift heavy loads with minimal effort. Chains are often used to transport heavy loads.

roller chain

Whether using a roller chain as a drive chain or a belt conveyor can be tricky. Whether it’s a small low-speed drive with manual lubrication or a high-speed pump-lubricated drive with multiple sprockets, there are several factors to consider when choosing a roller chain. First, you need to consider motor horsepower and rpm. The speed of the motor determines how much chain you need. For example, if you are using a low-speed drive, you will need to choose a low-pitch, high-pitch chain. Another thing to consider is chain length – ideally, you can go for an even number of sprockets and chains, but never go smaller.
The lubrication system is also important because the lubrication system must be able to deliver enough oil. The type of oil used to lubricate a chain depends on its operating environment, temperature and speed. Wear is caused by pressure on the bearing, angular sliding of the pins, and rotation of the rollers. There are five different types of lubrication methods available, depending on the system used. A high-quality carbon steel chain is a major advantage when operating at high temperatures, as it can withstand higher temperatures.
The materials of construction for roller chains vary by application. Typically, the most common materials are steel and stainless steel, but sometimes alloy steels are used in food processing machinery that may have lubrication problems. Nylon and brass are also sometimes used. Some industries require heavy-duty chains. If you need an extremely heavy chain, you may want to consider a heavy-duty roller chain. If you are not sure which type of chain is best for your application, consult an industry expert.
Unlike other chains, roller chains are more efficient from a size and weight perspective. While solution chains are useful in some situations, drive chains are more effective for dirty work and slipping on tracks. They are commonly used in construction and manufacturing. There are other advantages to using a drive chain. They are generally stronger than belts, which is a huge benefit. So, if you’re wondering which is better, here are them:

Multi-strand roller chain

The multi-strand roller chains for drive chains market is expected to grow at a CAGR of over 20% during the forecast period. Market reports cover product demand, supply, and cost. The report covers the global market including company profiles, product details, and contact information of key players. It also takes into account the revenue generated by different application areas. The report contains 159 pages of useful information and data. It is an essential tool for anyone involved in drive chain manufacturing.
The essential characteristics of multi-strand chains are their power ratings and allowable bearing area pressures. Power rating is an important characteristic that determines the chain’s ability to transmit a specific load. Typically, multi-strand chains are rated in the range of 12,000 watts per strand. However, their capabilities are limited by link plate fatigue, roller impact fatigue, and wear between pins and bushings.
Energy Series chains are ideal for high-speed and high shock load applications. The chain is designed to provide reliable power and withstand the rigors of the oil and gas industry. It uses high-strength steel and double-coated rolls. These chains come in different lengths and come in two types: single-strand and multi-strand. It is best to consult a professional to find out which chain best suits your needs.
The global multi-strand roller chains market is expected to grow at a CAGR of over 7% during the forecast period. From 2011 to 2019, the industry is expected to grow by nearly 6%. However, the outlook for this market is not optimistic, with some companies experiencing negative growth over the past year. Nonetheless, slowing global economic growth and tightening COVID-19 regulations are likely to hinder the market growth.
Although requirements vary by application, it must be remembered that the load on a multi-strand roller chain must not be greater than 1/9 or 1/6 of the tensile strength of the chain. If the load exceeds this threshold, the chainplates will fatigue. This is the main reason why roller chains are expensive. However, this is not always the case. Multi-strand roller chains are a great idea if you are looking for an affordable and reliable drive chain.

double chain

If you’re looking for an industrial-grade drive chain, you’ve probably considered a double chain. The chain meshes with the sprockets on either side of the gears. It comes in different styles, each with its own advantages and disadvantages. The CZPT duplex series has twice the power capacity of standard SC duplex chains. This type of chain is usually best for new applications. On the other hand, SC double chain chains are the cheapest but have less weight and power capacity.
Another option is a triple drive chain. This type of drive chain has an additional row of plates and contains three sprockets. Its unique design reduces the weight and impact velocity of the timing chain. It is usually used in automotive applications. It is ideal for low to medium-load timing applications. It is also available in acoustically optimized versions. Three-quarter inch pitch double chain chains are widely used in gasoline engine aids and timing drives.
chain

flat top chain

High friction rubber is usually installed on the top or bottom of a flat top drive chain to improve its high friction surface and prevent interference during side bend conveying. The chain plate can be customized with thin rubber layer or thick elastic polyurethane rubber according to customer requirements. In addition to providing high friction, the flat top chain also provides excellent anti-slip properties for glass bottles.
Premium steel flat top chain with high quality surface finish and excellent wear resistance. They have a high level of noise reduction and can be used in heavy duty conveying applications. These chains are available in a variety of alloys such as stainless steel or aluminum. Some models are designed to be very rugged and last longer. Aluminum and galvanized steel chains are popular choices for these chains.
Flat Top Drive Chain Conveyors are versatile and come in an endless combination of configurations. Drives can be connected end-to-end to form long conveyor lines, while side-curved flat-top chains are versatile enough to handle tandem, serpentine or carousel configurations. Standard and heavy duty models are also available. Flat top chains can be used in many different applications including food, beverages and other commodities.
Standard flat top chains are usually rectangular or L-shaped and designed for use on straight conveyors. In some cases, space constraints may require a U-shaped or rectangular conveyor line. For smoother conveying, side-curved flat-top chains can be used. These chains are paired with regular rectangular chain plates and tall pins for high load capacity. They come in different widths, including multi-strand chains.

China Custom Promotion 13mm Black Lifting Chain Hoisting Chain   bush roller chain driveChina Custom Promotion 13mm Black Lifting Chain Hoisting Chain   bush roller chain drive
editor by CX 2023-04-22

China Black Leather Rope Chain Obster Clasp Wax Line Leather Cord Jewelry Accessories Gemstone Pendant Necklace Chain Rope roller chain assembly

Jewellery Results Type: Chains
Substance: Leather-based
Solution Identify: Rope Chain

Our ServicesWe have opened a shop in HangZhou Intercontinental Trade City for more than 10 several years, experiencing clients from all in excess of the globe, we have prosperous encounter in export trade, We can make nearly all the CZPT jewelry on the market place. As prolonged as you place ahead your requirements, we can customise.
Organization Details

Packaging & 2571 Sailing Jewellery Bikini Waist Bead Set Colorfu Tummy African Midsection Bead Human body Chain Beaded Tummy Chain Delivery
FAQone. Might I have a search at the sample very first? Sure, we have sample services, you can decide on to order samples. 2.Can you give me a discount on this product As a actual manufacturing facility, we make and market our items by ourselves, so the earnings of our products is really minimal and the cost of our goods is extremely affordable. We can appear down a bit if your buy is at least a lot more than 1000. three. What type of logistics providers do you supply? How prolonged will it just take to get there? It will get there at your handle in about 3~10 working times through DHL, HangZhou manufacturer custom made ab muscles personal computer inject molding plastic inject plastic component UPS, EMS,PX. Or we can supply the goods according to your specifications. 4. Can you customise our products? Of system, very first of all, you can ship your products to me. I will give you the quotation after I obtain them. Following every thing is organized, P&M OEM Stomach muscles PP HIPS injection&rotomolding mildew areas plastic injection mould supplier you require to spot an purchase in our keep, which will take us about 10-thirty times to produce. We are the actual manufacturing facility, all organic CZPT products on the industry can be completed. 5.Do you have right after-sale services? Relaxation assured, we have a expert consumer service team, if you have any inquiries ahead of or soon after product sales, ab muscles plastic go over mould injection molding Car parts plastic areas producing customized layout manufacturing unit you can feel cost-free to speak to us.

Advantages and Disadvantages of Drive Chains

Drive chains are widely used for sliding steel guides. While solution chains are often used, roller chains are more efficient in size and weight. Nevertheless, a drive chain is often the best choice for dirty jobs. The following are some of the benefits and disadvantages of drive chains. Learn more! Adapt your vehicle to your specific situation with drive chains. You’ll be glad you did! Read on to learn more! Continue reading for information on different types of drive chains.

Inverted tooth chain

An inverted tooth camshaft drive chain has teeth on its links and two pin rolling pivot joints that engage each other to transmit moderate to high-speed rotations. This type of drive chain is also known as a silent chain drive, which is particularly effective in reducing noise and vibration. The teeth on the links mesh perfectly with the teeth of the gear sprocket. The inverted tooth design also provides smooth communication of chain links with the teeth of the sprocket.
The design of the new model was particularly effective in quelling noise. The “Druid” spring forks enabled the chain to adjust with minimal motion of the axle. It was launched at the 1910 Olympia show and sold more than 500 units. The drive chain was also silent, which reduced the need for sound insulation and attenuation components, which in turn minimized weight. Hence, it became an ideal choice for wind turbines.
The main disadvantages of chain drive include its low speed and limited range. It is expensive to manufacture and requires precise mounting. Maintenance is essential, including lubrication and slack adjustment. Its velocity fluctuates as the chain is stretched. This causes the chain to fail at the worst possible time. The chain drive also has problems associated with slippage. In addition, it can be prone to excessive wear and tear. Fortunately, however, there are newer types of drive chains available, which are more durable and reliable.
chain

Duplex chain

There are three types of duplex drive chains: SC, RP, and Ramsey. Each has their own unique advantages and features. The Rampower duplex series offers twice the power capacity of the standard SC duplex chain. They are often used in new applications. SC duplex chains are the most affordable and are used in less demanding applications. The SC duplex chain has a lower power capacity but lower weight. There is also no guarantee of performance.

Multi-strand roller chain

The Multiple-strand roller chain for drive chain market can be defined on the basis of the factors that drive growth in this industry. The factors that hamper market growth can be understood in order to come up with alternative bends for lucrative opportunities. This report aims to understand the current scenario and the impact of COVID-19 on the industry as a whole. We will also discuss the market drivers and restraints. We will discuss the various types of Multiple-strand roller chains for drive chain and their market sizes in the coming years.
The minimum tensile strength for a roller chain is one sixth or one-ninth the tensile strength of a conventional drive chain. These standards are established to prevent linkplate fatigue, which is the main cause of premature breakdown. A chain made of this material is considered a superior choice for high-performance applications involving a high load-bearing capacity. If you’re using a drive chain, make sure to choose a proper chain based on the type of application. A simple chain with a high load-bearing capacity is also ideal for simple applications.
While it is true that a high-tension, high-speed drive requires a higher power rating than a low-speed chain, roller chains are primarily used in low to mid-speed applications. They are similar to bicycle chains but may have a master link. In motorcycles, chains are heavier and may require a chain tool to remove. These chains are often replaced with toothed belts or a combination of both.

Flat top chain

The flat top drive chain is a versatile conveyor belt that conveys medium and large workpiece pallets. Its arcing capacity makes it suitable for continuous drive combinations involving curve arcs. The flat top chain is also available with PA wear pads on the workpiece pallets. The flat top chain’s steel and plastic glide profiles allow surface loads of up to 1.5 kg/cm. HD profiles are compatible with the flat top chain.
The steel flat top chain is available in several types: 815, 820, and 881 series. These are heat-treated to have high strength and excellent wear resistance. They can also be used with various sprockets, including 820 sprockets. The high-quality steel chain can be used with many industrial applications. However, if you are looking for a durable chain for your industrial application, iwis hardened stainless steel flat top chains are an excellent choice.
TSplus flat top drive chain offers the most flexibility of any conveying media. The drive units can be linked end-to-end to form extended conveyor lines. Side-flexing flat top chains are available to create serpentine, in-line, and carousel conveyors. Drive units are available in standard and heavy-duty models. They are versatile enough to handle a variety of container sizes. If you need a more complex conveyor system, you can choose a heavy-duty drive chain.
Rexnord flat top chains come in two basic styles: MatTop chain and TableTop chain. The TableTop chain is molded in standard widths ranging from 3.25 inches to 12 inches. These are shipped in ten-foot sections, but you can also find 20-foot-wide mattop chains. You can even customize your MatTop chain to meet your exact needs. They are perfect for a variety of conveying applications, from general conveying to wash down applications.
chain

Conveyor chain

Drive chains for conveyors come in a variety of styles. These chains can have varying degrees of pitch. Pitch is governed by wheel tooth strength, the overall chain rigidity, and the type of drive motor. A normal maximum pitch is determined by the width of the link plates and the angle between the mounting angles. You can increase the pitch of your chain by strengthening the bushes between the link plates. Make sure that the gap between the wheel teeth and the bushes is approximately one-fourth inch.
Pitch and tension of the chain are important considerations when choosing a chain. The minimum pitch is determined by the thickness of the tooth on the wheel and the maximum pitch is determined by the rigidity of the link plates. However, this maximum pitch may be exceeded with bushes between the link plates or clearance with the wheel teeth. A good quality chain will have bearing surfaces lubricated to prevent excessive wear and rust. Medium-viscosity mineral oil is suitable for normal operating conditions. SAE 20W-50 is a good choice for this application. Self-lubricating chains are available from many chain manufacturers.
The chain is usually lubricated by dripping oil between the links. This type of lubrication requires regular inspection of the conveyor chain. The amount of oil should be enough to prevent reddish brown discoloration on the chain joints. A lubricating oil should be applied on a daily basis, according to the manufacturer’s specifications. In order to ensure a longer life for your drive chain, make sure that you lubricate it on a regular basis.

China Black Leather Rope Chain Obster Clasp Wax Line Leather Cord Jewelry Accessories Gemstone Pendant Necklace Chain Rope     roller chain assemblyChina Black Leather Rope Chain Obster Clasp Wax Line Leather Cord Jewelry Accessories Gemstone Pendant Necklace Chain Rope     roller chain assembly
editor by czh2023-02-14