Main achievments for project machine     

    We started producing large spring for grab machine industry and heavy machinery industry of our country from 1968. Main customers we are serving are Liuzhou Project Machine Plant, Tianjin Heavy Machinery Plant, Harbin First Project Machinery Plant, Tianjin Engine Machine Plant, China First Tractor Project Co.,Ltd, Baotou 447 Plant, Kunming Heavy Machine Plant, Xuanhua Project Machinery Plant, Beijing Contraction Machinery Plant, Shandong Bulldozer Plant of HQ, Shandong Automobile Re-assemble Plant and so on. The springs we produced for these customers have small winding rate and high rigidity and are high-quality products, so all of them have got high evaluation.
    We also produced pedrail tension spring for Korea Dayu Yantai Doosan Co.,Ltd in 1997. They were strict with the metallogenetic and decarburized layer. After examination, the springs we produced can satisfy their demands perfectly. A batch production of R220, S250 tension spring and S290, R300 tension spring was done for Yantai Doosan Heavy Industry. From the second half year of 1999, we have been producing seven types of spring R225LC-7、R210LC-5、R220LC-5、R305LC-7、R375LC-7、R455LC-7、R245-7 for Changzhou Modern Project Machinery Co.,Ltd.
    After technology improvement, we can supply 60 thousand pieces for 30 thousand grabs annually. We have designed NC double-side grind machine for project machinery spring. So the work efficiency was raised by 400%, and realized automation, which is first done in China spring industry. Besides these merits, the quality of the spring was remarkably improved too.
    We can ensure the quality of project machinery spring we produced: nonmetal impurity is according to JISG0555－77, and can reach d60×400≤0.25％; grain size is according to ASTME112，eligibility level is above 6, quantity of oxygen ＜25PPM. For this reason the intrinsic quality of the spring is radically improved and the customers are quite satisfied with our product.