Why Use Coral Draw

Why Use Precision Cold Drawn Products?

In addition to the significant cost and time savings precision cold-drawn products provide, companies often evaluate precision cold-drawn products when they:

• Are having a difficult time making a product
• Are working with a material that is difficult to shape or form
• Don't want to invest capital to replace worn out machines, retool machines or add capacity
• Are using their equipment infrequently and can't justify the expense
• Can benefit from the reduced machining associated with near net shapes
• Are buying from machine shops and find the cost expensive
• Lack the skilled labor to produce precision, high-quality parts or who can't find skilled craftsmen

The Benefits of Cold Drawing

• High quality
• Increased mechanical properties
• Improved machinability
• Longer tooling life
• Tighter dimensional tolerances - Cold drawn tolerances as close as .0003 inch vs. hot rolled only to .060 inch
• Better surface finish - Cold drawn finish as good as 63 RMS vs. hot rolled to only 250-plus RMS
• More consistency of dimensions (bar-to-bar and end-to-end)
• Tighter straightness tolerances matched to your specifications

Why You Should Consider Cold Drawn Special Profiles

Precision cold drawn products not only provide significant cost and time savings, they can also save you significant capital and labor costs. You should consider precision cold drawn products if you are:

• having a difficult time making a product
• working with a material that is difficult to shape or form
• ready to replace worn-out machines, retool or add capacity
• using your part-making equipment infrequently, and you can't justify the expense
• able to benefit from the reduced machining you get with near net shapes
• unable to find the skilled craftsmen to produce precision, high-quality parts

Reduce Your Parts Production Costs By Up To 70 Percent

If you're using machined parts or making your own, you can save up to 70 percent of your production costs by switching to cold drawn, custom profile shapes. Simply specify the exact solid bar shape you need, then cut off the parts as you need them. You minimize or eliminate machining, hand operations and scrap loss. Our cold drawn parts are so precise, that often the only additional processing required is drilling, tapping, threading or countersinking.

Slipforming is a construction technique which has been used for decades for production of concrete structures. Wide range of structures are slipformed, typically, vertical structures such as towers, bridge columns and offshore platforms and horizontal structures like rigid reinforced concrete pavement, canal lining etc. Apart from vertical structures with uniform thickness, slipforming technique is also used where geometry of structure and wall thickness changes. Slipforming is a continuous working operation (24 hours a day), which requires planned supply of materials, management and supervision. Problems that occur during this process need to be solved instantly. Slipforming involves complex operations as compared to other construction techniques.

Vertical Slipforming

A slipform consists of a framework of horizontal walings and vertical yokes. The slipform panels are connected to each other on inside of the walings. Each side of slipform is connected to vertical yokes that keep panels in position. The jacks for lifting of form are installed on horizontal crossbeam between yokes. When slipform is lifted, all the jacks are activated simultaneously. Hydraulic driven jack is most commonly used.

Figure 1 : Typical Sections through vertical slipforming

Principles of vertical slipforming are illustrated in Figure 1. The slipform panels normally have an inclination in vertical plane in order to make panel self-clearing in relation to concrete wall. The inclination depends on stiffness of the slipform panel and concrete pressure. The slipform panel has variable stiffness depending on position and dimension of each yokes and walings. Slipform operation is a continuous working process where the slipform is kept close to full of concrete while it is lifted stepwise. The concrete is placed in 100 to 250 mm thick layers whenever the freeboard height is sufficient. The slipform rate is adjusted so that initial set in concrete occur between 200 to 400 mm above bottom of the panel. Depending on inclination of panel, concrete detach the slipform panel above the hardening front where concrete skeleton is rigid enough to resist back sliding. The slipform rate is planned based on complexity of concrete structure, skills of the work force and available inventory of materials. The setting time of concrete is adjusted to fit planned slipform rate. The setting time of concrete depends on the temperature, concrete composition, and properties of the cement.

Slipform Components and Their Functions

Yoke Legs Yoke legs are used to lift the slipform structure as one integral unit, transfer lifting reactions to jacks and acts as the main connecting member for walkway platforms, masons’ scaffold, yoke beams, top platforms, etc.

Walkway Bracket (Inside and Outside) Inside and outside brackets are connected with the respective yoke legs with the help of a pin for easy erection and dismantling along with a pipe strut to support cantilever portion to facilitate placing of concrete, placing of reinforcement, vibration, fixing inserts, block outs, pockets, etc.

Shutters and Walers The function of shutters and waler assemblies is to maintain correct profile of structure to be slip formed and resist concreting pressure.

Lifting Jacks Lifting jacks facilitate lifting of Slipform assembly. Jacks are to be suitably located preferably at equal intervals to enable to lift slipform as one integral unit. Capacity of jacks is decided depending upon the reactions at point of lifting.

Jacking/Climbing Rods Jacking rods are normally located centrally in the wall to be cast or at equal distance in yoke beams depending upon the number of jacks. The jacking rods are generally of 48mm, 32mm, or 25mm in diameter based upon the capacity of jacks. The lifting jack climbs over the jack rod. The entire load of the Slipform assembly is transferred to jacking rods when jacks are energized.

Hydraulic Pump Hydraulic pumps are provided to circulate required quantity of hydraulic oil at desired pressure for energizing jacks to lift the assembly and facilitate its uniform lifting.

Tapered Sleeve Tapered sleeve tubes are provided to prevent fresh concrete coming in contact with jack rods, thus, facilitates extraction of jack rods later. Taper sleeves are attached to yoke beam and move along with slipform and create a hole in concrete around jack rod.

Advantages of slip formwork

The advantages of the slip formwork include:

• High speed of erection (works’ execution speed increases) and as a result, rapid completion of the project - considerable saving of time;
• Rapid completion of the elevator machine room constructing process, time saving through quick installation of elevators, installation of water and electricity supply;
• Minimal use of a crane, as formwork is lifted by hydraulic jacks;
• Optimal quantity of scaffolding and work platforms as the slip formwork system presupposes the use of its own platforms for implementation of works. This helps to maintain cleanliness and order at the construction site, because there is no redundant material to be stored;
• Uniformity of wall sections with the project drawings, smooth wall surfaces are achieved by the use of slip formwork, which cannot be said about other formwork systems;