UL is Underwriters Laboratories (Underwriter Laboratories Inc.) shorthand. UL certification is through terminals terminals UL safety test, the portion of the terminal through the UL safety test terminals, is America's most authoritative, but also in security testing and identification of large private institutions in the world. It is an independent, non-profit, do testing for public safety professional organizations. It uses scientific methods to study the test to determine the extent of a variety of materials, devices, products, equipment, construction of life, property and whether the harm; determining, write, issue the appropriate standards and help reduce and prevent life loss of property information, while carrying out the facts research business. English definition UL: UL Underwriter Laboratories Inc. is a shorthand. UL310 is relevant certification quick connect terminals. UL certified terminals: Underwriter Laboratories Inc Terminals UL Development History: 1890s 1894: creation of UL UL founder of Williams Merrill (William Henry Merrill) Mr. founded the "underwriting Electrical Engineering Bureau" (Underwriters Electrical Bureau), namely, "the Department of Electrical Engineering of the National Bureau of Fire" (Electrical Bureau of the National Board of Fire Underwriters) predecessor. March 24, 1894, Engineering Bureau conducted its first test, the test object is "Mr. Shields" non-combustible insulation. 1895: the results of the first year UL has only three full-time employees and an annual budget of $ 3,000, a total of 75 reports issued to clients. Bus and bus or bus and the electrical terminals, when the bolt lap joint terminal design, should meet the following requirements: a, hole diameter and length of the various types of lap lap bus connections comply with the specifications in Appendix C of the regulations, Use a torque wrench to tighten the steel bolt torque values ??connected to comply with this specification appendix D; b, busbar contact surfaces clean, grease-coated composite electricity sales terminals, no glitches around the bolt holes; c, connecting both sides of the bolts have flat washers, There are gaps between adjacent washer more than 3mm, nut side washers or spring-loaded locking nut; d, bolt by force, not to the electrical terminals subject to additional stress. Terminal processing | electronic products factory Song Chong-wook (certified) | Shanwei terminal provided by Dongguan Shijie Xu Song Chong electronic products factory. Dongguan Shijie Xu Song Chong Electronic Products Factory (chuangxs.1688.com) is Dongguan, connectors leaders, over the years, the company is implementing the scientific management, innovation and development, the principle of honesty and trustworthiness, and satisfy customer needs. Song Chong-wook in electronic products plant leadership with the staff warmly welcome all inquiries negotiations to create electronic products factory Song Chong-wook a better future.