Once bent parts in the purchase of improper selection, production costs will rise, bent parts can not be expected to recover the costs. Therefore, there are several factors to weigh when making decisions to be.

1. Artifact: The first important item to consider is that you want to produce the parts, the point is to buy a table to complete the processing tasks and the minimum tonnage smallest machines. Carefully consider the material grade and the maximum processing thickness and length. If most of the work is the thickness of 16 gauge, the maximum length of 10 feet of low-carbon steel, so free bending force need not exceed 50 tons. However, if do a lot of bottom forming die, perhaps you should consider a 150 tonnage machines. Well, assuming that most of the material is 1/4 inch thick, 10 feet free bending requires 165 tons, while the bottom die bending (calibration curve) would need at least 600 tons. If most of the artifacts are 5 feet or shorter, the tonnage almost halved, thereby greatly reducing acquisition costs. Length of the part to determine the specifications of the new machine is very important.

2. Deflections: You have to consider this machine deflections may occur. Under the same load, deflections 10 feet machine table and slider appears four times five feet machines. That is, the shorter the machine requires less shimming can produce qualified parts. Reduce shimming and shorten the preparation time. Material grade is also a key factor. Compared with the low-carbon steel, stainless steel load usually need to increase by about 50%, while most brands of soft aluminum reduction of about 50%. You can always get the machine from the bent parts vendor tonnage table that is displayed in different thicknesses, different materials under tons per foot of length required for the number of estimates.

3.Bending radius parts: Then, shall focus on the bending radius of the part. When using free bending, bending radius of the die opening of 0.156 times the distance. In free bending process, the die opening distance should be eight times the thickness of the metallic material. For example, 1/2 inch from the opening formed 16 gauge mild steel, part of the bending radius of about 0.078 inches. If the bend radius is almost as small as the thickness of the material, shall be carried out with bottom forming die. However, the concave bottom molding pressure required than the free curved about four times larger. If the bend radius is less than the material thickness, to adopt the tip radius smaller than the material thickness of the punch, and resort to imprint bending method. Thus, we need 10 times the free bending stress. To free bending, the punch and die by less than 85 ° or 85 ° processing (small something is better). When using this set of dies, pay attention to the punch and die gap in the bottom of the stroke, and resilient enough to compensate for leaving the material remains over bent approximately 90 °. Generally, spring angle bending die in freedom bent parts on the new generation of ≤2 °, bending radius equal to the die opening of 0.156 times the distance. For bottom bending die, the die angle is generally 86 ~ 90 °. Between the bottom of the stroke, the punch and die should be a slightly larger than the gap of the material thickness. Forming angle can be improved, because bottom die bending tonnage greater (about 4 times the free bending), reducing the stress in the bend radius is usually caused resilience.

Embossing bending and bottom bending die the same, but the front-end processing punch needed bend radius becomes, and the bottom of the punch stroke gap is less than the material thickness. Due to exert sufficient pressure (approximately 10 times the free bending) force the punch tip contacts the material, the spring is substantially avoided. In order to choose the lowest tonnage size, preferably larger than the thickness of the material for the intended bending radius, and possible use of free bending method. Large bending radius, often do not affect the quality of its future use as member.

4. Degree: bending accuracy is a factor that needs careful consideration, it is this factor that determines you need to consider a manual or CNC bent parts bent parts. If the bending accuracy ± 1 ° and can not be changed, you must focus on the CNC machine. CNC bent parts slide repeatability is ± 0.0004 inches, forming a precise angle required to adopt such a precision and a good mold. Bent parts manual slider repeat accuracy of ± 0.002 inches, and in the case of a suitable mold conditions will generally offset of ± 2 ~ 3 °. In addition, CNC bent parts for quick loading mode ready when you need a lot of small quantities of bending part, which is the reason for considering an unquestionable.

5. Mold: Even if you have a shelf full of mold, do not think that these molds suitable to buy a new machine. Must check each mold wear, the method is to measure the length of the front end of the punch and die shoulder between the shoulder. For conventional mold, per foot deviation should be ± 0.001 inches, and the total length of the deviation is less than ± 0.005 inches. As for grinding mold, per foot accuracy should be ± 0.0004 inches, overall accuracy may not be greater than ± 0.002 
inches. The mold for the best grinding CNC bent parts, conventional mold for manual bending member. Indeed, we often make the bent parts only buy and not buy a new ancillary suitable mold mistake.

6. Bent piece side: a factor often overlooked is the material in front of bent parts bent side. Assume along a 5 × 10-foot 10-gauge carbon steel plate bent 90 °, bent parts probably have to exert additional pressure on the steel plate 7.5 t top up, and the operator must be 280 pounds heavier ready straight edge whereabouts . Workers manufacturing the parts may require several able-bodied or even a crane. Bent parts operations often require bending the long side parts, but do not realize how hard they work. There is now a care feeding means is adapted to engage in such work shop, this device can be modified according to the needs of new and old machines. With this arrangement, forming the long side parts only one operation.