Although there are many types of tapping screws, they all have the following similarities: Round head Tapping screw,hex tapping screw,flat head tapping screw,pan head tapping screw,truss head tapping screw Shenzhen Lanejoy Technology Co.,LTD , http://www.compressionspring.net
First, look at the seedlings and fertilize. In the process of topdressing, it should be classified according to different seedlings. In general, late seedlings and weak seedlings should be re-fertilized to increase the rate of tillering and panicle formation; strong seedlings should be less or not. At the same time, for the winter, there is no strong seedlings or few single plants, and the wheat fields with a total stem number of less than 400,000 per mu should be applied early and reapplied. Generally, 20 kg of tri-element sulfur-based compound fertilizer is applied per mu. For the wintering period, the individual develops well, and the moderately strong seedlings are less or not applied. The main control is to control the jointing fertilizer to reduce the breeding of ineffective tillers in Spring, prevent ridges from closing, and is conducive to ventilation and light transmission. For the Wang Chang Miao, which is too large in the group, in addition to controlling the fertilizer and water during the regreening period, measures such as deep tillage and chemical regulation should be taken to control the growth of wheat roots, stems and leaves.
The second is to look at the soil and fertilize the sand land because of the "small seedlings do not send old seedlings." If the fertilizer is poor and the water retention is poor, it should be applied more properly. If the fertilizer is insufficient, it will have a certain impact on the number of spikes and the number of grains and the growth in the later stage. Due to the poor performance of the previous fertilizer, the clay should be applied less during the regreening period. The extra-fertilization can be taken at the booting stage. It should be noted that the fertilization should not be excessive to prevent greed and lodging.
The third is to look at the fertilization of the sky. If it is raining in the green period, use the fertilizer spreader to apply the fertilizer. It is strictly forbidden to apply fertilizer to avoid burning seedlings, burning leaves and affecting wheat growth. Spreading fertilizers not only does not absorb wheat well, but also causes the volatilization and loss of fertilizer, resulting in unnecessary waste. In the drought, fertilize water in time to increase the utilization rate of fertilizer.
(1) are generally made of carbonized carbon steel (accounting for 99% of total production). It can also be made of stainless steel or non-ferrous metals.
(2) The product must be heat treated. Carbon steel tapping screws must be carbonized and stainless steel tapping screws must be solution hardened. In order to make tapping screws to meet the requirements of the standard of mechanical properties and performance.
(3) The product surface hardness is high, the core toughness is good. That is, "soft inside strong outside". This is a major feature of tapping Screw performance requirements. If the surface hardness is low, it can not be screwed into the matrix; If the core toughness is poor, a twist will break, can not be used. So "inside soft outside steel" is self-tapping screw to meet the use of performance, very important requirements.
(4) The surface of the product needs surface protection treatment, generally electroplating treatment. Some product surface must be treated by phosphate (photostatting), such as wall panel self - tapping screws for photostatting.
(5) Production by cold heading process. It is recommended to use high-speed cold heading machine and high-speed wire rolling machine or high-speed planetary wire rolling machine. High speed is emphasized here to ensure product quality. Only the head of tapping screw produced by high-speed machine is well formed and the thread quality is high.
Nowadays, the temperature will rise and wheat will enter a stage of rapid growth and development. The key period of wheat returning to green and topdressing will also come. Most farmers arbitrarily increase the amount of reclaimed green fertilizer when topdressing, causing wheat to fall and reduce production. In this regard, the author suggests that farmers should follow the "three look" to apply wheat to green fertilizer to ensure a bumper harvest of wheat this year.
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